Hehe. General user fuckup is of course a much more precise conclusion, particularly at the Uni of Bergen where I work
Not much of a prob as we've just migrated onto XP/2003 AD system and now just remote ghost the pcs, but used to be a real pain in the butt.
As for general fuckup, thats often what happens whan the user has installed pretty much all the shareware, mediaplayers, Bonzibuddy and super smart toolbars there are, and then decide to clean up by uninstalling all at once thru control panel. Since these have dubious strings attached just about everywhere, there's bound to be trouble.
As for corrupted, I'm sure you're right. Actual failed files are probably rare, but I suppose the corrupt part comes from the error msg you get when Javascript has been "fixed" by Symantecs (and probably any other) virus removal tool. I forget wether it was Nimda or whatever but had that exact problem over and over myself at work. Thus we swithched to Opera - problem solved.