I have found another way to rescue m2t HDV video when it has Vegas crashing errors. That is to use the program MpegVCR from womble.com and resave the m2t as a regular mpeg2 file. Doing this strips the transport info off the file but still smart-renders the mpeg video so there is no loss.
I don't know if this works all the time, but it did work on a clip I was just having trouble with yesterday. It also seems to be better than Mpeg2Repair in that I'm not having trouble with smart-rendering the clip into new projects.