There are small number of issues with using MOM2005 and WinSvr2003 SP1. Consider this a heads up.
49594 – Windows Server 2003 SP1 breaks MMPC alert and discovery forwarding. [KB 895951]
50432 – Push agent install fails on w2k3sp1 when MOM server installed using action account with no admin rights on target box. [QFE released April 4th, KB895195]
50436 – Consoles are unable to connect to remote management servers that are running Windows Server 2003 SP1. [KB 895952]
51199 – Access denied when trying to commit configuration changes as a MOM Administrator on a remote UI. [KB in process]
51209 – Remote procedure call failures after applying OS service pack 1 to W2k3. [QFE in the works, KB896989]
In addition there might also be an issue of a clean install of MOM 2005 Reporting on Windows 2003 SP1, which was related to SQL Reporting Services. The workaround to the issue is: http://support.microsoft.com/?id=896861
