It happens everywhere in XP
On the desktop if you put the mouse on an icon it tells you the path associated with that icon.
Open up control panel and put it on an icon another little box pops open telling me what the icon is.
As Spannersatcx said I think what occurs on this site is a function of this site and although I find it irritating that I can't have the mouse anywhere in the thread column without a description occurring there's probably nothing I can do about that.
It's just that after all these years of using windows I really don't need to be told what the icons are before I click on them.