If you've done a 100 Blu-Rays you have more experience than I do in this area. Regardless, I'll throw in my two cents – which is to suspect a problem in your source video.
Try Blu Ray encoding to HD with another source file of >7 minutes. If that works, go back to FCP and create a new project and copy the old sequence to that project. Try again to ecode in Compressor with job action set to HD.
If there's still a problem, take a look at your content at roughly 6:20 into the sequence and replace,
Thanks for the info. I tried a different movie, same procedure and it stopped at 5:40 this time and has been frozen there for an hour now. It seems like it is encoding, but wont burn the Blu-Ray. I have "burn BluRay" selected, and the correct drive. Like I said Ive done this many times before.
Thanks Mike G
Trying to narrow possibilities. And so much for the corrupt project/clip theory. It sounds like it's not getting to the job action stage…that it's hanging while still in the encode process…correct? In which case it's probably not going to make any difference whether you set the output device to HD or your burner…but as a long shot you might try that on a short segment.
In addition to David's excellent suggetion to try Digital Rebellion's repair tool, have you seen these troubleshooting steps from Apple? The escalate in degrees of severity up to the point of reinstall. Prior to the stage of trashing preferences, I'd first do a simple reset of background processing (under the Compressor drop down menu) to see whether that cured it.