Pool mining - problem communicating with bitcoin rpc

[Rhimining]

Hi,

I'm trying to mine using guiminer on a gpu and have recently starting gettin this error.. I have earned one or two btc on slush's pool.  Since yesterday, I have been unable to connect.  I've also created accounts on btcguild and bitclockers to see if the problem was with just one pool, but the error occurs with all.  I've tried disabling windows firewall, port forwarding 8333 to this pc and no luck so far.  Nothing major changed
From when I could mine to now.

What are the causes of this?  Any resolution?  Most threads on this issue are about solo mining