I don't think I've ever had this happen (on the desktop) with my copies of Windows XP unless I've switched resolutions. Then again, I don't keep too many icons on the desktop and I don't find myself using the Windows machines very much. But I did use one as a primary machine at work a few years ago and don't recall this "random" behavior (Win2K then XP).

MS hasn't improved anything since WinXP. Vista and 7 are pretty much exactly the same except for some new lipstick on the same old pig. In fact I was blown away the other day at how crap 7 was - gleaned in only 10 minutes, I have no plans to ever use it again. It's as if MS has only managed to add more layers of useless complexity to every part of the OS. They're going backwards.