Have you installed Microsoft NET Framework 2.0? This is needed for the Catalyst Control Center (but not Omega). I've heard that you can safely delete mom.exe without any adverse effects, but can't confirm this. If you delete it and notice any problems, reinstall the driver and Control Center, or just Omega if you prefer.
Are you currently using Omega or Catalyst? Did you follow the correct uninstall/reinstall procedure when swapping between the two drivers?