For several months now, we have been getting the following error from my production SharePoint 2007 box. It doesn't appear to affect operations; however, we need to upgrade to service pack 1, but our experience tells us that when you install updates on broken servers, bad things happen. Hence, we would like this error to be resolved before we perform the upgrade. The error occurs when we perform backups via stsadm and change settings via Central Administration. All backups complete without errors and the changes we make are always successful. These errors come in swarms of 3 to 5000. We have run stsadm.exe -o sync -deleteolddatabases 2, and that did not help. I've personally examined the Objects table in the database to look for orphaned databases, but I don't find any.
Source: Windows SharePoint Services 3
Event ID: 3351
SQL database login failed. Additional error information from SQL Server is included below.
Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'.