Had similar problems, resolved by removing a huge lump of fluff that had got itself stuck in the AGP slot.
Better to use compressed air rather than trying to blow into sockets, and do it at arm's length unless you want a face full of a dust - the quantity of which you didn't even realise was in there (voice of experience).
Better to use compressed air rather than trying to blow into sockets, and do it at arm's length unless you want a face full of a dust - the quantity of which you didn't even realise was in there (voice of experience).