A fellow mentioned this a few weeks ago, but just saw this for myself tonight. When saving a veg file, the "Copy and trim media" box works fine for DV files, but not at all for m2t files.
Unless I'm completely missing something, this is a pretty obvious and major bug, yes? Using V7d.
This feature has never trimmed any file except for DV and, perhaps, WAV. MPEG-2 and m2t have never been trimmed because Vegas never had the ability to do "smart rendering" (i.e., cutting without re-encoding) for these files.
Perhaps someone can comment on whether Vegas 8.x can now "copy and trim" MPEG-2 and m2t files, since it has a limited capability to smart render this formats. I don't know since I still haven't gotten around to installing 8.x.
There are two related issues that should be addressed here:
1/ "Copy and trim" should work with all smart-renderable clip formats.
2/ "Selectively render" should also work with all smart-renderable clip formats.