As a recent MAC convert (still reading through the testaments of all the other mac users to find good applications which are freeware / shareware )  I came across a Windows Only application (go figure) that allows for a user to test all the versions of IE from 5 on up to 7.x  (well actually 8 Beta 1 now) It is called IETester - While this is a tool for the guys who are out there building websites - if you are using any of the WEC tools (typo3) it might be worth a look see.