<<<I've used Mac the Ripper to do a full (2 GB) disc extraction>>>
It was weird long before that. Where did you find a commercial movie under 4G? If you're reversing a professional or home-burned DVD, you don't need Mac the Ripper.
Final Cut has never been able to import Video OBjects (Transport Stream MPEG2) directly. You always have to convert it to Something Else before you do that.
There are programs that try to import foreign flavors and succeed up until they run out of cache or buffer space (or hard drive space) and then they throw their little hands up in the air and give up.
Also, you know that the first time you try to produce with Transport Stream, Final Cut has to convert the show to Uncompressed Video and the file sizes go through the roof.
The same thing happens much worse when you try to decompress H.264. What do you mean my 1.2G movie just turned into a 0.478 TeraByte video file?
You doing this on your laptop?
Koz