I had a very similar issue. It ended up being network hardware related. Try bringing your proxy machine and cube to a friend's house and connecting there.
Could you elaborate on the network hardware issue?
I am having a very similar issue and I have noticed that right before it automatically restarts, long polling will become inactive, then it restarts at almost 8 min 40 seconds exactly. I don't see how a network hardware issue like a router could cause the cube to restart like that.
Could an ISP be causing this somehow? I can try at a friend's house but if the ISP is the reason, then I won't be ruling that out. Thanks for the help, much appreciated.
bark0de, did you fix your issue?