I just wanted to chime in here about the long polling/restarting issue some people have been having. My cube worked fine on one network. When I moved it to a different location/network, I started having the same problem. This is a network problem. I haven't been able to determine what exactly the problem is or how to correct it in my situation, but I do have a kludgie work around that got my cube up and mining again by using two different proxy machines as primary and backup.
The cube mines for a little while, gets stuck on the one proxy, fails over to the other proxy, mines for a little while, and back and forth. It takes a bit of a performance hit this way, but it's currently the only way I can get the thing to mine on the network it's currently on. Hope this helps...