FCP 7.0.3 hangs on Edit to Tape with SCC captions

So we can edit to tape all day long if we don't add an SCC file in the Mastering tab. But as soon as we do add an SCC file, FCP 7 hangs when trying to do an Insert or Assemble edit, with a spinning beachball. In the Final Cut Pro 7.0.3 Release Notes I found this (We are using this version):

Fixes several issues with closed captioning .scc files and Print to Tape/Video including:

• Outputting to AJA Io HD now preserves closed caption data.
• When outputting the same sequence multiple times, users can choose different .scc files.
• Print to Tape/Video no longer hangs with certain types of .scc data and Snow Leopard.

"Print to tape" and "edit to tape" are different beasts. Does SCC caption insert work in Edit to Tape or is this broken? We need to do an Assemble edit onto a digibeta tape.

Regarding our caption file - it comes from the WGBH Caption Center, the people who basically invented closed captioning. I know it's good because it works fine in a DVD and on some H.264 files we've made. We did need to change the linebreaks in the file to Mac (they were Windows linebreaks in the file from WGBH), or Edit To Tape would throw an error that the file wasn't readable. This is nothing unusual. When we get Mac formatted files we have to do the reverse to make them readable on our Windows-based DVD Authoring system.

Any ideas? We need to edit a ton of stuff to tape starting next week, all with captions.

When Apple (very opaquely) says "certain types of .scc data" does anyone here know what they're referring to? Is it commands in the SCC data itself, or the formatting of the file or what?

Thanks,

-perry