www.makemkv.com

Looks like you are correct - I returned the disc to the store & the new one seems to work fine. Thanks!

Whole series of "The source file '/BDMV/STREAM/00017.m2ts' is corrupt or invalid at offset xxxx" messages. Also, the program hangs for a while - with debug on it just hangs forever (well, OK, I didn't let it run that long). Without debug it exits with a "Failed to save title 0 to file...