I was getting the "Can't Sumbit to Queue" error and tried everything. I downloaded the Compressor Repair utility and I still got the error. I deleted prefs and plists and still got the error.
Finally I went to Apple support and deleted all the files listed to remove FCStudio and did a complete reinstall. Still, when I try to submit I get the error. Now I'm stumped and screwed. When I did the re-install I didn't install Soundtrack, only to save time. Shouldn't have made a difference. Any suggestions will be appreciated. This is frustrating since I did a new install.