I think I found a bug in Final Cut Express

[situs_inversus]

Or I'm just missing something really obvious and am going to feel dumb.

Got a copy of FCE 4.0.1 around? Try this:
 

1. select Timeline
2. File > Export > Using Quicktime Conversion...
3. under Format, select Quicktime Movie (if it's not already selected) and then options
4. click to change Size (or something)
5. click on another program, say Chrome for example.
6. click back into FCE, set the size, click Ok.
7. you're fucked.

Now you cannot get to the movie settings dialog, you cannot save, you cannot cancel, you have to force quit. How does one report bugs to Apple, anyhow?