The only places I can think of is System Preferences>Sound or View>Video Out>Refresh Video Devices. In the Video Out choices there are a number of settings that effect firewire devices and how they connect, you might jag the right setting there!
There are some settings that can be adjusted in the Tools>Voice Over tool but that's for incoming audio. Might be worth a try.
Trashing the FCE preferences will reset FCE to it's original state, so that may sort it. Repairing permissions and a re-boot are also things that won't hurt.
Otherwise???
Al