Adobe Reader 8/9 on XP, freezes on program start

Did some searching, haven't had any luck here or elsewhere on the web.

Sticking Adobe Reader on a new machine; basically a fresh install of XP SP2, with plenty of HD space and RAM. Tried installing both Adobe Reader 8.1.3 and 9.1.0 - both versions install with no errors or messages of any kind. However, trying to open a .PDF or start the program manually makes the app freeze.

A check of Task Manager shows AcroRd32.exe eating 95%+ CPU, and it needs to be killed from there to unlock things. No previous versions of Reader on this machine, and everything I've found elsewhere online points to Adobe choking on temp files that flat don't exist.

Oddly enough, checking back with older versions, Reader 5.0.5 works relatively normally save for the whole inability to open newer/fancier PDFs.

I've been asked to put Adobe on this box, so Foxit really isn't an option.