My Admin Panel died After an Upgrade (but only in Firefox)

I recently got free web hosting from a fairly good provider and installed wordpress using the “autoinstaller” that they provide. While that install went well, I found out that they were only providing a very outdated version (2.0.5) and decided to upgrade to 2.3.2 before I spent any time with customizing anything. I followed all the instruction and the upgrade appeared to work: until I visited the admin page, which was just plain blank. After logging out, clearing the cache and logging back in, I was able to see the admin page, but only for half a second before it somehow redirected Firefox to the same blank screen as before. The admin panel still works in IE7, but I prefer not to use that abortion of a so-called web browser (and at home, don’t even have the option since I run Linux)

Has anybody else had this problem and how do I fix things?