[MX2004] Can't Open External Library, including HaloTheme.fla

I am having trouble opening the external libraries of certain FLA files, most notably all the theme files (ex. HaloTheme.fla). When I try to import them, they are greyed out. I am using OS X, but when I try to do this in Windows I have no problems. Is there a bug with MX 2004 in OS X, or am I doing something wrong? I can open HaloTheme.fla by itself just fine. I just can’t import it’s library.

I’ve tried reinstalling Flash. I’ve made sure that the document I import into is AS 2.0, I’ve checked to make sure these files aren’t locked, etc. A friend of mine also using MX 2004 in OS X is having the same problem.

Any ideas?