I'm having the same problem but I think it might have something to do with getting updates. I have done a manual download of updates and the problems goes away for a few days, but then it returns.
I have called AVG and they said I was the first caller with this problem, so they were no help. They said remove their software and see if the problem continues.
I will try uninstalling and reinstalling but I feel this will be a short term fix until it wants an update.