I wasted a bit of time trying to find and modify the TrustedSAPHosts.config file in the 12 hive. The document clearly states that the config file is actually somewhere else, but out of long habit, I kept bringing myself to the 12 hive.
It was a little more complicated for me because the right location in my environment was really d:\program files\Micorooft Office Servers\12.0\Config
Hope this saves someone some time!
--Paul Galvin
http://paulgalvin.spaces.live.com