Hopefully...
it is just run-of-the mill nasty cookies or malware causing your problem. I can't do without the following list.
CCleaner
AdAware
MalwareBytes Anti-Malware(MBAM)[paid license]
SuperAnti-Spyware
SpywareBlaster
and of course I mentioned Avast already. CCleaner works amazingly well for getting rid of temporary files or cookies that interact with those misbehaving files.
I've been playing with the new MBAM outgoing malicious IP blocker, and I've found everytime I can't open a page, it is because of temp files trying to communicate with a bad server that is blocked by host file or MBAM. If I run CCleaner, it instantly fixes the communication problem, because it gets rid of the offending files FAST!
AdAware with AdWatch does this automatically, but I really like MBAMs IP blocker, as it tells me who the malware are trying to communicate with. Then I run a WHOIS search on that IP to get an idea who the bad guy is - providing it isn't some private address inside an ISP - in which case there isn't really a solution.
CCleaner is a quick, fast, down, and dirty solution that doesn't need signature files, so I like cleaning with it when researching bad sites. You must be logged into a standard account to keep safe on this - though. Perhaps you've heard of the limited account in Windows?
I have read that occasionally someone's account at FB gets compromised, and the owner has to change their password and have FaceBook reset the account to fix the infection or settings problem they are facing. Google for FaceBook security settings, to get a good look at how to configure your profile for security properly at FB.
FaceBook will never be secure, but at least one can mitigate the problem some.
