OOPs I guess I goofed, it was SpyBot S&D immunize, but the same principle I suppose, a "signature match" but the match is being improperly interpreted by GIANT A.S. since it is not due to actual installed spyware.

Hmmm .. do you mean, if you rightclick and exit the Microsoft A.S entry in the tray, that is leaves a process running? It loads these two processes at startup {assuming set at startup defaults}:

1. gcasServ.exe -- MS AntiSpyware Service
2. gcasDtServ.exe -- MS AntiSpyware Data Service

Are you saying it leaves one of those running? I suppose if it did you could "kill" the service using Task Manager if you wished. ;)