Has Final Cut 7 been broken by current Mac OS?

I've been away from FCP for a little while and all of a sudden it's impossible to link video and audio clips together. They are not linked after digitizing even though "Sync audio capture to video source if present" is checked in User Preferences. They will not link with command L, nor by selecting Link in the Modify Menu. I tried trashing preferences thinking they were corrupt, but that made no difference. FCP 7.03 running on OS 10.8.4.