Last week I was called in to client with SBS2003 server. Quickbooks, SQLserver, BackupExec (which uses SQL server) services had all stopped and would not restart. I reset the passwords for each system account. No luck. They appeared to not have adequate permission >> I tried to do a Runas for each account to start a CMD shell and it failed. So I added DomainAdmin to each account and it works fine now.
Today, I was called and Outlook Web Access was not working. Error, Login timeout 440. Again, I added DomainAdmin privileges to IUSR_STS1 and OWA started working again.