Not able to Assign Permission to a new Linux User

Hello All

I recently installed VMware Server 2.0 64 bit on one of my server. Everything is UP & Running fine BUT i am not able to Assign Permission to any new user that i create in Linux. When i click on 'Permission' >> 'New Permission' >> 'then select user and add it to a Role'  & then Click OK i get an

ERROR

"The server response included one or more errors

If these problems persist, please contact your system administrator

DETAILS: RuntimeFault: Database temporarily unavailable or has network problems

"

I installed VM on CentOS using 'root' user.

thanks for you assitance in advance