Microsoft Surface Pro has just hit the market, but the tablet is already sold out at some retailers, prompting questions about supply.

More specifically, many are wondering whether Microsoft simply faced overwhelming demand, or if it staged a limited release on purpose.

The 128GB Surface Pro has quickly sold out at the company's online store, and continues to remain out of stock. The 64GB version, meanwhile, is still available and ready to ship. On the other hand, Best Buy indicates shortages of both versions across the board. The retailer doesn't sell the Surface Pro tablet online, and only a few physical Best Buy locations have the 64GB and/or the 128GB versions in stock.

Staples lists the 128GB model as an "online only" offering, but it is out of stock. The 64GB model is available only in select locations, and stock is scarce.

The shortage is not only frustrating for those who tried to purchase a Surface Pro this weekend, but it also raises questions once again about Microsoft's retail distribution strategy.

When Microsoft launched its Surface RT slate, it went under fire for crippling demand by selling the device only through its stores. Microsoft has now made deals with more retail partners to sell its products, but still it can't seem to properly handle supply.

Tech Web sites and blogs oozed with reports of fruitless attempts to buy the Surface Pro. According to many user reports, most Best Buy and Staples locations they contacted had received only a few units or, in some cases, just one tablet.

According to corporate vice president and Surface head Panos Panay, Microsoft is working to fix the shortage issue.

"We're excited for the response to Pro," tweeted Panay. "Some are having trouble getting it. Sorry you're having to wait. We're working hard to get u Pro ASAP."

The Surface Pro is the higher-end version of Microsoft's tablet, and comes with a price to match: $899 for the 64GB version and $999 for the 128GB model. It packs an Intel x86 processor under the hood, allowing it to run Windows 8 Pro and virtually any software written for the Windows ecosystem. Its ARM-based RT sibling can run only Windows 8 style apps formerly known as Metro.

The Surface Pro faced mixed reviews and received some criticism for its battery performance and storage capacity, but plenty of users were still interested in purchasing the slate. Most of those users, however, were out of luck, as the Surface Pro supply seems to be quite scarce.