Oracle OEM issue on Windows Server 2003 after Windows .NET security patch
If your Oracle enterprise manager 10g running on Windows Server 2003 started to impact database performance and constantly consuming CPU, it could be related to Microsoft patch.

smallwei 12:52 pm on May 18, 2010
In one situation, after applying Microsoft .NET Framework 2.0 Service Pack 2 Security Update for Windows Server 2003 and Windows XP for x64-based Systems (KB974417), our Oracle Enterprise Manager 10g started acting up and constantly hammering our database and consuming CPUs.
As soon as we rollback the patch everything started to go back to normal.