Jason,
It never worked for me either with XP and any IE XP supported (8.2 was the last I tried I think).. But I had loads of other problems with IE under XP, changed to Firefox and all worked fine - Also worked with Google chrome.
Problems I had (if I remember right) were:
1.) could only see first line of incoming PM
2.) Blank page when trying to open message
3.) Unable to compose or send messages
I dealt with this at first by having both Chrome and IE (I hate Chrome) and using Chrome only for PM.. Then when IE was being rejected by more sites etc, I made the switch to FireFox and have never looked back.. Wonder why I stayed with IE for so long..
Does Windows 8 have an XP compatibility mode perhaps? could this be the problem?
Fred.