Say, Old Gimmer, not to worry about the IE5 folder. You have a subdirectory under Temporary Internet Files directory named Content IE5 whether you're running IE6 or not. Under the Content IE5 folder you will have several subdirectories with a random set of numbers and letters for names. It's just the way MS has the TIF (browser cache) set up.
Probably they started doing it that way when version 5 of IE was the latest version and saw no need to change the folder name when IE updated. Also you have to Show hidden files
in order to see it so I guess they figure most people wouldn't bother. But it causes consfusion because scanners will list that directory. But it's perfectly normal.