Nokia’s (NOK) Lumia 920 has been in short supply in several regions, and a debate ensued regarding whether the stock-outs were due to solid sales or short supply. According to channel checks performed recently by T. Michael Walkley and his colleagues at Canaccord Genuity, the answer is “both.” Walkley and his team recently performed their typical checks to gauge U.S. smartphone sales for the month of November, but his findings this month were more interesting than most.

In a note to clients on Monday, Walkley wrote that Apple’s (AAPL) iPhone 5 was the top-selling smartphone in the country last month. No surprise there.

The analyst also said that Samsung’s (005930) Galaxy S III took the No.2 spot in the U.S. in November. Considering Samsung recently reported Galaxy S III shipments topped 30 million units in 150 days, this also isn’t much of a surprise.

At AT&T (T), however, things got interesting last month.

We reviewed the Nokia Lumia 920 early last month and while we loved the smartphone and the software, we feared history might be repeating itself. Nokia’s last flagship phone featured the same great hardware design, the same Microsoft (MSFT) operating system and the same attractive $99.99 price tag, but it was a flop.

While the new Lumia includes new hardware features and a newer version of Windows Phone, we wondered if it was compelling enough to attract consumer attention. In these early days, the answer appears to be “yes.”

“While our checks indicated the Lumia 920 was the top-selling Windows smartphone at AT&T and #3 selling device at that channel, we believe iPhone dominated AT&T’s sell-through volume,” Walkley wrote in his research note. He also stated that according to his checks, sales of HTC’s (2498) Windows Phone 8X topped the Lumia 820 at T-Mobile and the Lumia 822 at Verizon Wireless (VZ).

Early sales at a number of European carriers are said to be very strong as well, though Walkley did pump the breaks a bit by noting that “limited initial supply was cited as the reason for early post-launch stock-outs at some carriers versus overwhelming demand.” Walkley also questions whether or not Lumia 920 sales can remain strong in the coming months as new handsets hit the market.