SD loads slowly only in Firefox

Yesterday, the Straight Dope boards started loading veeerrrrrryyyy slowly on my main computer, only in FireFox. I can’t figure out what’s going on.

What it looks like it’s doing is not caching any graphics. So all those little envelopes and arrows and various little icons that show up when you’re looking at a forum are being downloaded one at a time and every refresh takes several seconds.

It’s gotta be something with my FireFox; it works great in IE and Google Chrome. Works fine in FireFox on another computer.

I’ve checked all the obvious things. Disabled all my add-ons. Cleared my cache. Rebooted the computer.

I can’t find any page-based settings for caching in Firefox - is there one?

Any other ideas?

This is driving me nuts.

Forgot - clearing cookies helped a little bit. Better, but still not as zippy as it should be.

Logging in/out didn’t seem to do anything.