javac invalid flag

I'm using IDEA 5.1.2. I've never had a problem building before, but now I've started getting an error every time I try to build.

The error is:
Error: javac: invalid flag: /usr/local/dev/projectX/src/server/src/SOpen/spm/dao/.

The path listed is one of my directories containing java files. I can't figure out what is causing this problem. I don't have any problems building with ant. Any help would be appreciated.

Thanks,
Jason