Don't think I can replicate. I've been trying all kinds of weird stuff. I'm just beginning to get a handle on the interface, but not there yet by a long shot. I've seen FCP X crash a couple of times too. Running on a newish iMac Intel Core 2 Duo w 8 GB of RAM.
I think I know what may have happened. I believe I may have expanded an audio/video clip. Created an overlapping audio edit then I had a collapsed the clip. After doing this, the clip appears on the timeline indicating that audio is starting at a different point than it actually does. Are they calling this a new "feature"?