By Katie Marsal

Published: 07:50 AM EST

The poor reception of Windows Vista, along with a strong Mac OS X, will help Apple continue to ship Macs at three times the industry average by the end of the spring, according to BMO Capital Markets.

While most observers are focusing on iPhone 3G, it's the Mac sales that should help drive Apple's quarter ending in June, BMO analyst Keith Bachman explains in an investment note.

The researcher maintains that Apple should ship between 2.4 to 2.5 million Macs over the three-month period and that this would equate to about a 39 percent year-over-year surge in Mac shipments -- 3.2 times the predicted industry average of just 12.2 percent.

Competitive pricing plays a part in the increased sales. Bachman notes that while Apple's lineup isn't always immediately comparable, a 2.4GHz MacBook at $1,300 is often priced only a few dollars more than the average $1,292 paid for a 13-inch notebook while running faster than most; other configurations trade storage for speed but are still close enough to sway some buyers.

Ironically, however, it may be Microsoft driving customers into Apple's hands. Ongoing jitters regarding bugs and performance in Windows Vista a year and a half after its launch are believed to be driving would-be Windows upgrade customers towards Macs, which are considered by the analyst to be less problematic, simpler, and more secure.

"Thus far, user satisfaction ratings for Vista have been weak, and startup times for Vista have been known to be much slower than the Mac OS X," Bachman says. "Thus, more than 50% of recent customers buying Macs in Apple retail stores are first-time buyers."

He adds that the combined effect of better hardware and software should spill over into 2009, where Macs will help Apple grow shipments 26 percent year over year and could result in just over 3.9 percent world marketshare.

BMO's researcher also estimates more positive news for Apple as a whole in the short term, including the predicted launch of new MacBooks in August that should spark more sales, a halo effect stemming from iPhone 3G, and retail expansion through coming months that increases Apple's exposure in the marketplace.

Notably, Bachman also raises the possibility of an iPhone 3G shortage between launch and the end of July. Although it would limit sales in the short term, it could paradoxically help Apple's share price by suggesting a warm reception to the cellphone's release.

"We believe it is quite possible Apple will run out of phones, post the July 11 launch [but] in the month of July, given some recent production yield issues," he says. "However, we
believe that Apple will be able to catch up with phone demand during the quarter. Hence, from
a stock perspective, near-term lack of availability issues could end up being positive... with headlines reading something akin to near-term demand outpaces supply."