Hi,
notsavvy, and welcome to the forums.
Glad you figured it out - although you might want to do some hardcore malware testing to make sure you aren't infected with something that is infecting downloads as they are written to disk....
Might I also recommend Fx 3.1 B2 - it's a lot faster than Fx 3.0.x and most extensions / addons work well, since you have the option to override compatibility if it does not work the first time around....