try a hard-refresh (clear all cache)
i cant log in!

Doesn't this problem contradict with you being able to start a forum topic?
Soory, I'm being unhelpful.
Try clearing your cache or try a different browser to see if it's firefox that's screwed, or its just your internet.

It could be related to this problem ...
Google mistakes entire web for malware http://www.theregister.co.uk/2009/01/31/google_malware_snafu/
although that one does seem to be fixed.
It is more likely to be caused by an unexpected change to the security settings in your browser, probably in the area of pop-ups. Try different bowsers if you can (especially try IE7). Make sure that pop-ups are enabled for chess.com.
for about the past 2 or 3 days i havent been able to log in... it goes as far as the "logging in...please wait.." screen and ive been waiting for hours now... ive tryed it several time ..i use firefox 3.0.. it just sits on that screen with the little white and grey bar still moving... please help!