Compressor-Unable to submit queue-Any solutions yet?

Below is a common problem with compressor I am now experiencing. In the past and on the web there are many many references to this problem with no simple solution. Has any one heard of any new fixes for this problem?, or just anything that works to fix it. I would like to use compressor again,

Compressor-Unable to submit queue

Please restart your computer or verify your Compressor installation is correct.

I did ugrade to dual core intel mac pro recently

mac pro OSX 10.6.8