I used to have a similar problem running Fox on Ubuntu, but never did figure out which was causing the problem: the OS or the browser. In the end, one of the updates must have fixed it. I also went and did a delete/reinstall on the major browser plugins (Flash, Java, etc.) and that seemed to alleviate some of the issues. I, too, hate IE.
I remember I also used to have problems because my default MTU setting was a little off. It would manifest itself as repeated load errors trying to upload pics to FB, forums, etc. the damn thing would just spin and spin then time out or cancel itself altogether. TCP Optimizer will fix it on a Windows machine, Ubuntu has it as a generic internet connection setting.
~Marrow