My Selenium Grid setup is as follows (all VMs)

VM1 - Windows 7 x64 - Grid Hub + 2 RCs registering the default *firefox environment

VM2 - Windows XP x32 - 2 RCs registering the default *firefox environment

VM3 - Windows XP x32 - 2 RCs registering the default *firefox environment

I'm happily using Mbunit and Gallio to drive the Grid, but my problem is that sometimes the Grid hub will stop passing executions over to 1 or more of the RCs, despite their showing available on the hub console. They seem to be happily maintaining their heartbeat back to the hub, but they're never asked to do any more work. This is after they had been executing tests earlier in the test run.

Does anybody have any ideas why this should happen? In every case I've observed this behaviour, the last test an RC executed, before it then seemingly gets ignored by the hub, passed, and the session was successfully closed. Interestingly, whenever it happens to more than 1 of the RCs, its always (so far) been the pair that are running on the same VM. Yet they're managing to maintain their heartbeat, so it isn't a network connectivity problem.

Any help would be greatly appreciated!