Firefox and XP here and I don't see this issue? Version 3.0.12 Firefox (which I thought was the latest given I tell it to let me know if there is an update.. but took a great deal of time getting 3.5 into an Ubunto distro I also run here on a different machine?)
I do have the "enable Javascript" option enabled, I could imagine if that wasn't ticked various pages would look screwy.
Regards