anti virus's  

Try reinstalling your browser and messenger software. If it doesn't work, then the last way is to format your drive and reinstall windows.

hi
panda creates this kind of problems sometime
it may be because your cache must contains some kind virus affected files which was deleted by panda.
you just check your cookies because the problem you are facing is mostly happen due to problem in cookies.

I suggest that you uninstall panda antivirus and use AVG instead. I have no problem with AVG.

I know of several ppl who have had the same prob it also happens with norton antivirus.The best answer I can give you is to try the free avast virus engine
at avast.com.You have search a bit to find it on their site but they do have a free
(home user )engine that works very well.I have it installed on my laptop and tower
and have had very goo results with this program.The best part is it is free.
You have to register with avast with your email address and they send you a key
good for one year.hope this helps you out a bit.
Ps.You will have to uninstall panda(hope you didn't pay for it?)If you
did the panda site has a help centre/faq page that you can try to see if
anyone else had the same problem and how to fix it.

may be panda has left some registry setting as it is or may be internet explorer setting is remain unchanged on uninstall. with some registry tool (may be advanced system optimizeer) you can repair registry and check restricted sites option in Ie to remove any such sites restriced.

this does not resolve your problem then you are required to reinstall internet explorer

ofcourse instead of panda try avg 8.0 its free and better then any other freeware virus scanner.