Looks like the software glitch that plagued early versions of the handset — and prompted Nokia to offer replacement devices to consumers affected by it — hasn’t had much of an effect on inventory. The company says that far more consumers have opted to patch their Lumias with the software Nokia has provided than have swapped them for new ones at a local AT&T store.

In other words, if the cyan version of the Lumia 900 is out of stock at AT&T’s online store (as it currently is), it’s because it’s sold out for the time being, not because Nokia is scrambling to update and recertify returned handsets.

“The inventory situation is primarily a function of demand because we are seeing that most customers are opting to keep their units and simply update via Zune,” Nokia spokeswoman Karen Lachtanski told AllThingsD. “So the impact of customer swaps is insignificant. We are producing more devices to satisfy demand as quickly as possible.”

That’s a good sign, indeed. And further evidence that sales are exceeding expectations, as Paul Roth, AT&T’s president of retail sales and service, recently claimed.

Indeed, it appears that the device is selling so well that it’s tough to even find one right now. AT&T’s online store lists both versions of the device — cyan and black — as temporarily out of stock. At Amazon Wireless, the cyan version is back-ordered. And four of the five AT&T stores I called told me they had run out of stock.

Which is good news and bad for the Nokia, AT&T and Microsoft triumvirate — if the stock-outs are demand-related.

Good news in that the Lumia 900, the most eagerly anticipated Windows Phone device to date, is off to a good start, despite an unfortunate software glitch that prevented Internet access for some early customers. Bad news in that Nokia and AT&T don’t seem to have a supply sufficient enough to put a 900 in the hands of everyone who would like one.

There are a few caveats to this, however. It’s possible that these stock-outs may not be demand-related. They could, for example, be caused by Nokia’s offer of replacement handsets to consumers whose Lumia 900s were affected by that software glitch I mentioned earlier. While it’s likely that most of those consumers opted for a downloadable fix for the issue, it’s also conceivable that a number of them might have swapped their devices for new ones at a local AT&T store. And that clearly would have an effect on inventory.

Another possible reason for these inventory issues: AT&T’s Lumia 900 stock might have been depleted if it returned handsets potentially affected by the software glitch to Nokia for updating and recertification. Though I have no insight into it, I imagine that process would take some time. And it would likely have inventory implications for AT&T’s online store, and its local outlets as well.

AT&T and Nokia both declined comment on the issue.

The Finnish phone maker reiterated that customers can either download and install the patch or exchange their phone at an AT&T store. Nokia had originally said to expect the software update to be ready by Monday.

“Consumers now have the opportunity to update their AT&T version Nokia Lumia 900 software through Zune and Windows Phone 7 Connector for Mac earlier than anticipated,” Nokia said in a statement.

All Lumia 900 customers, regardless of whether they have had problems, will get a $100 credit, Nokia U.S. head Chris Weber told AllThingsD earlier this week. Customers that buy or order a Lumia 900 before midnight PT on April 21 will also get the credit.

That effectively makes the device free, for now, since AT&T had been selling it for $99 with a new two-year contract.

Nokia has gotten plaudits for its prompt and generous dealing with the issues. However, the glitches still threaten to diminish the launch of a product seen as key to the ambitions of Nokia and Microsoft to take on the top smartphones and re-establish themselves as serious players in the U.S. market.

The issue was particularly unfortunate given the teaser campaign that Nokia had run, touting that the arrival of the Lumia 900 meant that “the Smartphone Beta Test was over.”

Nokia U.S. chief Chris Weber told AllThingsD that the problem is a memory-management issue with the phone’s software, and is not tied to any hardware issues or to a flaw with AT&T’s network. The connection problem affects only a limited number of customers, Weber said.

Nokia has created a software fix, and all customers can swap their device at an AT&T store for an updated one or download a software update starting around April 16.

“We’re already manufacturing devices with the new software,” Weber said. “Those are being shipped to AT&T stores.”

The company is offering a $100 credit to all customers, regardless of whether they are encountering the problem. The $100 credit is also being offered to any customer who purchases a Lumia 900 before midnight PT April 21, effectively making the device free.

“The customer always comes first, and I think we’re showing it here,” Weber said in an interview.

Weber said the cost of the program depends on how many people purchase Lumia devices through April 21, and said that the expense was not the issue.

Nokia, he said, was focused on “how do we do something unprecedented for any inconvenience, (and) pleasantly surprise the customers.”

Nonetheless, the issue is clearly not the way the company hoped to launch what is designed to be a flagship product aimed at reestablishing the company as a major smartphone presence in the U.S.

“Obviously you don’t want these things to happen,” Weber said.

AllThingsD’s Walt Mossberg noted in his review that he experienced some other issues with the 900, including problems loading Internet Explorer pages over Wi-Fi.

Weber hopes the company will be remembered more for how it handled the problem than for the issues themselves. And, he said, visits to six Chicago-area stores on Monday affirmed for him that enthusiasm for the Lumia 900 is strong.

“We’re seeing incredible customer excitement and buzz,” Weber said. “I think we have a very compelling device that customers are excited about.”

Nokia, Microsoft and AT&T are all counting on big sales for the device and have said they are putting unprecedented marketing behind its launch.

Oddly, though, the product went on sale on Easter Sunday, a day when most of the Microsoft and AT&T stores that carry the device were closed.

As for how such a significant issue could have made it through the company’s testing processes, Weber said, “That’s something we are doing a current investigation on.”

It’s particularly unfortunate given that one of Nokia’s marketing pitches for the Lumia 900 was an online and TV ad campaign saying that the Smartphone Beta Test was over, and encouraging existing smartphone owners to trade in their “beta” Androids and iPhones for a real smartphone.

And — diverging from the current social gaming trend — it’s not available on Facebook.

The game, called Glitch, is comprised of thousands of hand-drawn illustrations — it’s a multiplayer online fantasy world that takes place inside the minds of 11 giants.

It is less like FarmVille and more akin to Activision Blizzard’s very successful World of Warcraft — except that there is no war. Instead, players must rely on their imaginations to build a nonviolent community of made-up characters.

In the company’s fact sheet, one question asks, “What can I kill in the game?”

The answer: “Your time!”

While that’s a genuine answer, it will be interesting to see if there’s a wide enough audience willing to invest a lot of time in a game without blood and violence.

The game, which targets adults 14 and older and has been available in beta for the past few months, is being called “a collaborative simulation,” where the direction the world takes requires cooperation among the players.

Glitch’s universe is a fantasy land, with plants that look like a hookah pipe with eggs at the end of each tendril. Strange palm-tree-like animations have googly eyes and tongues hanging out, and users can dress their avatars up as space crusaders or in dinosaur or unicorn outfits.

Tiny Speck’s CEO Stewart Butterfield said he doesn’t expect to attract as many players as a top game on Facebook, but added that he expects engagement among the players to be much higher. “We don’t need tens of hundreds of millions of people to play. We need a couple hundred thousand players to break even,” he said.

The game will be monetized through microtransactions — such as buying new outfits for your avatar — or through subscriptions. Butterfield said the company purposely avoided charging for simple things — like more energy in order to play for longer — even though that’s a popular way to get people to pay in free-to-play games.

“It creates a weird experience. It’s like stop signs with dollar signs,” he said.

While Tiny Speck is not on Facebook, the company does expect that the social gaming craze will be beneficial, as players introduced to gaming will seek out deeper experiences elsewhere once they get tired of playing different variations of the same farming-like mechanics.

“I think social gaming companies are burning their customers out. That’s the best possible position for us,” Butterfield said. “We are trying to bring beauty and brains to the online gaming world. There’s humor and absurdity. We have a low-level fundamental belief that there’s an importance of fun in everyday life.”

Even though it is not focused in the hot social gaming space, Tiny Speck has been the recipient of venture capital from some of the big-name Valley VCs, including Andreessen Horowitz and Accel.