I'm using GUIMiner with btcmp.com which was working fine last week (I'm a rookie, BTW). Today, I get these errors:
2013-09-03 09:55:36 Listener for "Default": rr.btcmp.com:8332 03/09/2013 09:55:36, upstream RPC error
What does this mean and what should I do to get mining going again?