The ask:
Record a sax player / keyboardist along with 3 MP3s and send the results to another Sonar user who is out of town.
 
Mistakes:
24/48 Project... this was a mistake because the original recordings were at 96 and this meant that the audio couldn't be copied from mine to theirs.
 
I recorded all 3 songs in a single project. This bugged the person I was doing it for because he wouldn't be able to tell what was what. I labelled all the tracks of course and told him, but it bugged him.
 
While recording the first track, the sax player wanted to see the music for the tune. I dragged the recording to the time bar to set the tempo to the tune (and now for all the other tunes too since they were all starting at the same time in the same project). I dragged the audio for the song into a midi track so he could read the music. He really liked this, but now the tempo was non-standard. We did loop recording around one section in the song in the middle.
 
The other Sonar user asked me to split the project into 3 bundles and convert the audio to 96. Should be easy right? I made 3 bundles at 48 and opened them. Next, opened an empty Sonar project at 96 and imported the audio one track at a time and exported it back over the audio in the audio folder for the uncompressed bundle. This is how I know to convert a project to a different sample rate, but it didn't work well at all.
The problems:
- clips were truncated (I have no idea why... the 48 clips unzipped from the bundle were not truncated)
- after opening the project (now all 96) the quick comping clips were all moved around and I couldn't remove them.
- there was a significant amount of silence at the end of the project making all the audio tracks way too long.
 
What I learned:
Basically, all of the cool things you can do with Sonar became a problem when I needed to convert the projects sample rate.
Loop recording creates one long Wave file totally dependent on Sonar to make sense of.
 
If I had it to do over again...
1. I would use 3 separate projects for the 3 songs.
2. I would make sure I used the same sample rate as the out of town project.
3. I would not allow loop recording in the middle of the project.
4. I would do no speed comping for the musician so he could hear what he'd done. I'd leave it 'un-comped'.
5. I would keep the tempo map flat at a single temp. Do not drag the song you are recording to to the time bar.
 
Could what I recorded be used?
Probably if I was there at the other guy's shop. I could get the audio aligned in his project. The bottom line though is that he isn't going to. He's going to chuck it and re-record it.
 
I probably spent 6 hours capturing the recordings, and 20 hours or more trying to get the recordings into a format he would accept.
1. I sent the full project initially split into 100 MB segments using 7Zip. (He rejected this as too hard).
2. He asked me to use some cloud sharing service but that gave me error and I couldn't upload anything.
3. I exported the waves directly and just sent him the songs he had given me and the audio tracks that went with them where the waves started at the beginning of the song. He should have been able to just drag these into the project and Sonar would have done the sample rate conversion. He said this was too hard and wanted a bundle.
4. I created a single bundle with all the work in it. He couldn't download it.
5. I put the full project and the project bundle onto a DVD and took it to one of his gigs and gave it to him. (He couldn't use this because it was at the wrong sample rate - first time this problem was uncovered).
6. I created 3 separate bundles at 48 with only the tracks for 1 song each. I unzipped the bundles to CWPs and converted all the audio in the audio folder to 96. I re-bundled the projects. But the recordings were messed up somehow. switching the audio in the audio folder was somehow a problem and clips got truncated and messed up. midi from the keyboard recording was a total mess. 
 
In the end, nothing will be used. It was a waste of time.

Hindsight is 20/20, but FWIW...
 
If he's using SONAR, he should have sent you Bundled (or Zipped) projects in the first place (my preference is to use .ZIP - smaller and less prone to re-open failures). That would have prevented the whole sample-rate issue, and also avoided sync problems that happen with MP3s because they necessarily always have some "dead air" at the beginning due to the compression process. It also would have ensured that the timeline was already synced, assuming everything was recorded to a click in the first place.
 
As you discovered, converting audio file sample rate outside of SONAR doesn't work as you would expect because SONAR stores the length of clips based on the number of samples. So when the up-converted file is referenced by the original clip, it ends up being truncated. If you down-convert, you get the opposite problem that clips have dead air at the end because there were fewer samples in the file than expected.
 
I think it's probably time for the Bakers to build-in a sample rate conversion capability, as the need comes up fairly frequently, and there's really no good workaround.
 
Otherwise the only option is to import audio into a new project that's been started at the desired rate or into a copy of the original project that's been stripped of all audio and re-opened with the new sample rate as the 'Default for New Projects' in Preferences. And this can be a chore, depending on how far along the source project is, and how the existing parts have been recorded.