Hi S,
This audit is for FDCC compliance. It is only an "Informational" severity level and FDCC Vista has this as "Not Defined"; this is indicative of the value in GPO, but if the service exists on the system, then it will technically be defined. So in all actuality, even though GPO states not defined, a system could have the service set to, say, Automatic (Delayed Start). The audit is actually recommending a definition of "Manual" which isn't necessarily a bad thing.
If you're not trying to follow FDCC compliance, you can disregard the audit.
Hope that helps.
Brian