The SPPersistedObject, PolicyConfigService Name=PolicyConfigService Parent=SPFarm Name=SharePoint_Config, could not be updated because the current use

when i was creating a Records Center in MOSS 2007, suddenly i had to encount for an error :

03/11/2009 10:44:59.45 w3wp.exe (0x0D44) 0x0D3C Windows SharePoint Services Topology 8dyu High The SPPersistedObject, PolicyConfigService Name=PolicyConfigService Parent=SPFarm Name=SharePoint_Config, could not be updated because the current user is not a Farm Administrator.

so the workaround for this error is :

1. Select you Web Site under Application Pools
2. Right click => select properties
3. Go to Identity tab and change the User Credentials to the same credentials that is being used to login to the Sharepoint Central Administration site.
4. Dont forget to do a iisreset.