A new report from one Wall Street analyst — Trip Chowdhry of Global Equities Research — says Mac sales have slowed significantly since the fourth week in July, suggesting its back-to-school promotion isn’t boosting sales as much as expected.

In a note to clients this week– as reported by “AppleInsider” (http://www.appleinsider.com) — Chowdhry said that the past weekend “was probably one of the slowest weekends for Mac sales” in the current calendar year, citing proprietary research based on “various tracking data.” He said Mac sales last weekend were “probably down” between 35% and 40% from the weekend of July 23.

He may be right, but all his research pretty much goes against the grain of every other report. For instance, this week UBS Investment Research analyst Maynard Um told clients in a note — again, as reported by “AppleInsider” — that Mac sales are strong. Um said his investigation in the retail channel found that demand for back-to-school computers has been “encouraging” and that the Mac remains very popular.

“Demand for Apple’s Mac computers remains robust as the brand continues to be the most popular among consumers and students heading back to school, which is consistent with historical trends of Apple outpacing the overall PC industry growth,” the analyst said.

Need more evidence?

During the 12 months that ended in late June, the Mac brand achieved an impressive 22.86% gain in revenue for a total of $20.38 billion, notes “Seeking Alpha” (http://macte.ch/RfvyC). Apple sold 3.76 million Macs in its fiscal 2011 second quarter, which is 28% growth from the year-ago quarter. That’s particularly impressive considering that the overall computer market contracted 3% in that period, according to the IDC research group. Also note that this was the 20th consecutive quarter that the Mac has outgrown the PC market overall.

Apple’s global growth is also accelerating. This week it was reported (http://macte.ch/6r6Yz) that the Mac’s sales are growing significantly in western Europe and France.

With all this ancillary evidence, Chowdhry may be right. But I don’t see it.

— Dennis Sellers