Lots of us have to trace down odd bugs and test things on different browsers and OS combinations… Of course, the worst of which is “various versions of IE” on “various versions of Windows”. It seems crazy, but the same version of IE can behave differently on a different version of Windows.
The two best solutions I’ve used are:
http://www.modern.ie/en-us/virtualization-tools [free, vm locally]
http://www.browserstack.com/ [costs, web based]
I just got assigned a crappy bug ticket on IE8 + WinXP and had to dust this off again… thought I’d send out a post, see if it helps others and triggers a discussion which might help me out too.