According to the latest retail numbers from the NPD Group for the second month of the December quarter on Monday, it appears Apple's sales were relatively flat year-over-year while sales of systems running the Windows operating system from rival Microsoft rose 7 percent. More precisely domestic Mac shipments were down 1% year-over-year in November even as industry-wide PC sales rose 2%.

Apple has generally been growing faster than rival PC makers, but NPD analysts put the overall flat year-to-year performance on comparatively poor sales of desktop systems, particularly iMac and Mac mini configurations, which the reporting firm claims are down 38 percent.

Let us begin with the fact that Steve Jobs offered only one-day Black Friday discounts on Macs of 5% to 10%, while competitors like HP and Dell were slashing already low prices as much as 50%. In a continuing trend, desktop sales were down 20 percent year over year. While Windows PCs saw a 15 percent decline, Mac desktops took a huge hit with a 38 percent nosedive in sales.

The tables turn when the notebook section is brought into discussion, as apple faired better in the notebook department, where a refreshed line of portables helped boost sales 22 percent year-over year during the month of November. Windows notebook sales rose 15 percent.

Moreover NPD also forecasts that overall PC sales will fall over 5 percent during 2009 to a $267 billion total, largely owing to economic uncertainty and belt-tightening amongst both consumers and businesses.

On Monday, Goldman Sachs analyst David Bailey cut his estimate for Apple's 2009 profit, warning "some nicks have started to emerge." Mr. Bailey warned the company faces "a tougher environment" in the first two quarters of next year, when he believes consumer demand will further deteriorate.