Well, I RTFM'ed and found my answer but I don't like it and am looking for a work around.

Audio/video events are saved in a new AVI file. You can trim DV AVI, uncompressed AVI, Sony YUV AVI, and CineForm AVI files. Because of the lossy nature of other video formats, those video files will not be trimmed, but will simply be copied to the project folder.

Is there any way to get trimmed clips from a 'non-approved' codec while save as/copy media with project? I'm using Canopus HQ which is reasonably loss-'less' but I guess Vegas doesn't know that...

New formats have been added to the "can trim" list over the years. You'll just have to try whatever formats you're wanting to use and see if they do.

Hmmph!

So, it is highly unlikely I'll be able to use this function with the HOURS of CanHQ footage I have?

Bummer. Oh, well...

Can anyone point me to the 'can trim' list please? More specifically, would I be right in guessing that footage created using Camtasia's TechSmith Screen Capture Codec is NOT on that list?

(Edward, if you see this, you might guess why I am asking!).

Pure speculation here, as I've not seen the "can trim" list, but, I wonder if this is related to long-GOP codecs. If the existing "trim and copy media with veg" save function doesn't do long-GOP, and, you could see why that might be so...

Well, then, you might be fine with TSCC, as it is an, um, intraframe codec, and not "lossy" at all - each frame is encoded individually, without reference to its neighbors.

Seems to make sense, thanks Seth.

The reason I asked is that I have been creating tutorials using Camtasia footage. I recently did a 'save with trimmed copies of media' and uploaded the files to an FTP site without checking them first. The five or six minutes I excised from around 20 minutes of Camtasia-produced footage ended up being the whole shebang (at several hundred mb), and because I had taken the best extracts from two Camtasia files, BOTH were uploaded.

Now, I'm unsure if I actually did the 'save as' or whether just the Camtasia footage wasn't trimmed. I've archived all the material off now so I don't have ready access to it but it would be useful to know for the next time.

AFAIK, the 'can trim' list is in my first post. Canopus HQ is not a long-GOP codec--vaguely similar to Cineform. And it will not trim clips.

I wonder if there is a registry key or something to edit...

Since Vegas 9 you can no longer trim to Cineform. It works perfectly in Vegas 8 but not in Vegas 9. I sent a ticket to Sony but they acted like it was a not a problem so I've had to move back to Vegas 8 for all of my Cineform projects.