I've built up a development 5.1 environment with a few hosts and vcenter running on a Windows 2008r2 vm (on a different cluster). I'm running all services including SQL express on the VM. After many fits and starts I've had a decently running vcenter service. Today I needed to reboot vcenter because it was dog slow (Thank you JAVA!!!) and add some more memory.
Now I'm unable to authenticate via the web client or the fat client. I've restarted the SSO service ("thanks" for naming that service starting with vcenter unlike ALL the other services vmware) per kb 2033137.
Fat client error is: "a general system error occured: Authorize Exception
web client error is: The authentication server returned an unexpected error: ns0:RequestFailed: Failed to connect to the identity source. Possible reasons include invalid user name or password, connection refusal, connection timeout, or failure to resolve hostname. The error may be caused by a malfunctioning identity source.
Judging by the plethora of threads about SSO on the forums I'm going to step out on a limb and say this service "aint ready for primetime" and I'm sure glad I don't have a production environment on 5.1 yet!