Sounds like a very similar problem like Avast had/has. In installation you needed to turn Network shield off. Or something like that. I can't remember it off-hand. I gotta go rummage the forums a bit to find it.
EDIT: The option that has to be turned off is called 'web shield'
Maybe the similar installation time option will solve the trick for you too. If you are willing at worst case to go through with un-install/re-install