Sanderxpander
 ... the simple fact is that Vegas does not allow you to simply replace audio and export the existing video stream.

That's not been my experience with Vegas 9 Pro.
I can easily replace any audio and re render (I'd not call it "export") the video, or any part of it,
with the new audio, even with the old audio in the project, as long as the old is muted,
or to take it further, even parts of the new audio and the old audio combined,
or just the video, or just the audio. It seems every imaginable option is easily available.
Slicing, moving clips, using volume envelopes or composite envelopes is very easy for me in Vegas.
 
To the OP.
Yea. Fix it in Vegas or any other Video NLE.
In Vegas if you need more room at the front just drag the video clip down the time line a good bit to give yourself the head room.
You can set tempo in Vegas and then tell the time line to show Measures & Beats, turn on snap, snap the start of the video
to measure 4 beat one. Render, import into Sonar project with same tempo and there ya go.
You can also disable all snapping and slide the video ( or audio ) by samples and get an exact start point lined up with a measure / beat or minutes:seconds:frames.
 

The problem is that you have to rerender instead of simply combining the existing video with new audio by remuxing. As far as I understand, this means an inherent loss of quality unless you're going for a completely lossless file format, in which case you'll end up with a huge file (way bigger than the original). The difference may be slight and you may not care, though. It may also be only for certain formats, but it has been my experience so far.

I never suspected that Vegas could remux. There seem to be other tools for that.
http://www.sonycreativesoftware.com/Forums/ShowMessage.asp?Forum=4&MessageID=861323
 
But that won't solve the OPs "slide the video" issue and since the OP want's to compose to the video
this implies that he's only working with a reference video and is not responsible for the final output.
So re rendering is no big deal.
Just send the newly composed audio to the producer / editor and they'll add it in the original project file along side the dialog and folly tracks.
 
Back to it...
The 'slide the video' problem is easily solved with Vegas or any other NLE that will allow setting tempo and viewing timeline by measures & Beats. Adding any desired count or number of bars in front of the video, or slip editing the video to a later start point is solved.
Then again, maybe a later version of Sonar will fix it by adding the same type of video engine Vegas is using.
P.S. Make sure your frame rates match exactly!

I agree, I just wanted to chime in and say even an expensive program like Vegas isn't a one-stop solution for people who are having problems working with video in Sonar. I recently bought it and while I have other uses for it, my first one was as simple as this and the results were disappointing.

Understood.
But to be more clear, expecting Vegas to remux isn't really relevant to problems working with video in Sonar.
It's a side issue and expectation about Vegas that has nothing to do with working with video in Sonar.

I believe Vegas, or any other decent NLE, can solve any and all problems that are actually only about working with video in Sonar.
 

Thanks Jean - very helpful post. Clipped to my Sonar OneNote notebook.

Ah so I'm not alone!!!!
 
 
I have a video which I need to start at  137813 in my project.......and have followed the Help here http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=Playback.46.html#1643946
but still getting Media Foundation as the video engine... the video is in .MOV format
 
 
HELP! How do I get my video to start where I want it?
 
Edit:
 
I am using Sonar Platinum - fully up to date
I do not want to fork out for a video editing suite just for this (simple?) task...