Microsoft appears to be using a picture of an Apple laptop on the cover of its Windows 7 launch documentation.
The cover of Microsoft's "Final Win7 Product Guide" shows a man sitting on his couch apparently using the new Windows 7 operating system on his laptop. His son - we presume this is his son and not a random child jumping on his head - is also excited by the new OS, so much so that he risks breaking his father's neck.
But canny-eyed Andrew Harrison, Reviews Editor of PC Advisor, noticed that the laptop in question appears to be not a recent PC portable but an old Apple PowerBook G4 Titanium - itself incapable of running Windows 7.
"I'm discounting Connextix/Microsoft VirtualPC as a solution, as it'd be too glacially slow to run any post-XP Microsoft OS," says Harrison, who once owned a couple of models of the Titanium PowerBook and is therefore intimately aware of what the back of one looks like - even with the metal port-defending flap raised.
See the suspicious picture below:
To make matters worse Microsoft appears to have tried to disguise the Mac laptop by crudely Photoshopping a Windows logo over the prominent Apple logo that was part of the PowerBook's lid design.
The Apple PowerBook G4 in question was current from 2001 until 2003. The first Mac laptop with an Intel CPU that could theoretically run Windows 7 was the 15in MacBook Pro from February 2006.
So either the man with the child on his head was using Windows 7 way ahead of time (in which case why, for heaven's sake, didn't he stop Microsoft releasing Windows Vista?) or he loves his PowerBook so much that he hasn't upgraded in around seven years.
Another explanation would be if Microsoft is suggesting that he owns a Mac but loves Windows so much that he has obscured the horrible Apple logo, and is only now ready to switch to Windows 7. Anyone else got a plausible suggestion for why else Microsoft would feature an incompatible, rival product on the "final" documentation of its most important software launch in years?
Microsoft has been accused of using Apple Macs in the past. We can't be sure of the veracity of the image shown on failblog.org and pictured here, but the possibility that the Mac in question could actually have been running Windows seems a poor defence of a company not even supporting its own Windows partners.
This embarrassment tops off a rather red-faced Windows 7 launch week for Microsoft. At the London launch - held at a club called Hospital... - the company demonstrators failed three times to get the touchscreen Windows 7 PC to connect to the Internet.
The first two times it didn't work they blamed the PC for having a loose cable. The third time it happened - or rather didn't happen - they just stopped trying.