A few days back, we were hit by a problem on one of our vCenter servers (vCenter 4.0 Update 1) in that the "VMware VirtualCenter Server" service starting failing.  The message in "System" event log was "The VMware VirtualCenter Server service terminated unexpectedly.  It has done this n time(s).  The following corrective action will be taken in 300000 milliseconds: Restart [...]