I use Firefox, and haven’t made any changes that I know of. But for me today on SDMB, the mouseover comments don’t show up, the post window isn’t working right (the url helper does nothing, smilies do nothing), the Quick Links link does nothing…??? Any ideas? I’ve restarted the computer, no difference. Windows XP
Correction: the Quick Links link causes the page to move down an inch. I just went to the sffworld forum which is the same software as this, and all the above problems work fine for me there. Popups are not blocked for this site.
Please delete this thread. I cleared my browser cache, all better now. Sorry. 
Most of the things you mention require javascript to be enabled. Make sure you have this enabled by going to Tools > Options > Web Features. The mouseover tooltips should work whether javascript is enabled or not, AFAIK, so I’m not sure what the problem might be here. Make sure you’re running the latest version of Firefox (1.0.6, I believe).
Ah. There ya go. Glad you got it working. 