Woody in the SBS forum posts up that if you are seeing KB978297 failing if you have Forefront installed on your SBS 2008 check out this info:
KB978297 has failed to install to several SBS2008 servers. The solution is detailed in the link. http://social.technet.microsoft.com/Forums/en-US/forefrontexchange/thread/e2f3b803-5b6d-4b66-ab85-3c408bc789c1/
A blog has been written on the Forefront site http://blogs.technet.com/b/fss/archive/2010/05/25/installing-rollup-1-for-forefront-security-for-exchange-server-service-pack-2-on-small-business-server-2008-fails.aspx
Note – that second link is missing in action. I’ll see what happened to it and blog back.
Update… hang loose the solution posted to the forum is not recommended. Stay tuned for more info.