If you have not found it already, there is a thread in the Apache section,
http://forum.ppcgeeks.com/showthread.php?t=11799., by user weedahoe.
Basically if you do not use Activesync to sync wireless sync to an exchange server, you need to configure it like you are going to use it for that, enter a fake IP, username and pass when prompted.
After you set up the fake connection, the schedule menu will no longer be grayed out. Then go into the schedule and select everything to "manual".
This way AS will not start until you launch it. It will still work over USB, BT, IR.