So this has happened to me somewhat intermittently before and it is annoying but it seemed to be MIDI tracks that were affected. Now however I have a VERY rudimentary project started and the main audio track (backer track) is doing it while speedcomping in another track.
 
Soo...
 
With three populated tracks, one is one long clip unsplit, the second is various takes split at relevant sections. The third clip is just a reference track for mxing and is muted.
 
1) I select a clip in track with all the takes.
2) Press Shift + Spacebar to start speedcomping playback.
 
Expected result: All tracks play with the track being speed comped slightly louder due to Dim Solo (which I do not like but that's another story).
 
Actual result: The first track with the long clip is completely silent while the track being comped is audible.
 
I'm having to manually Ctrl select the silent track (not the clip because that does other screwy stuff) and then it will playback. HOWEVER if I do something that deslects that track (like click somewhere or delete a take lane) I have to reselect it which is a pain for multiple reasons (one of which a confirmed bug manifests itself but I won't go into that).
 
The crazy thing is this seems to only happen with certain tracks and it mysteriously goes away sometimes. So far it is persistent with this project.
 
I am not sure if there is some procedural thing I am overlooking but I'm wondering if anyone else has experienced this. If I am doing something wrong I would certainly like to know but if it's a bug I guess I'm stuck with it for now (but if confirmed and it persists in Platinum based on other user experiences I'll post a problem report thread for the Baker's).
 
On a small project like this it's a pain but manageable. In my monster projects though it is a real problem especially when my MIDI drums are being silenced.
 
Thanks for any help. Cheers.

Sorry for the bump but I'm curious to see if anyone else has had this happen. I'm sure I'm just doing something wrong.
 
Cheers.

Yes, there seem to be some issues with the combination of Selection Audition (Shift+Spacebar) with a soloed track and Dim Solo enabled. This is difficult to reproduce consistently, but if you keep toggling Dim Solo and track solo on an off, eventually you can get into a state where either the tracks you should be hearing by Dim Solo are silent, or even the soloed track you're auditioning is silent. And sometimes solo button states change as you stop and start playback.
 
Dim Solo seems to have some issues in general that have been reported elsewhere, so I would be inclined to attribute the problem to that feature.

Thanks, brundle. I figured it might be a Dim Solo thing and agree that it definitely needs some work or to be completely divorced from the comping concept. I never used it before (or Audition for tracks) yet now because I'm a speedcomping addict I've had both those features and their quirks thrust upon me.
 
I mentioned that I think Dim Solo should have a fader (instead of the radio buttons) so the user can set the levels exactly how they want (I would just set it at 0dB so there is no difference while speedcomping) but now I'm thinking that there is no real reason to even have it associated with comping. If I'm building up a take I already know what I want to compare it to and what levels I need things set at. I think it should just take the mix, as is, and play it back during comping. Then if someone wants to engage Dim Solo for it they can.
 
As far as Audition I always found it to be a little unstable/unreliable. I get a lot of seemingly random audio engine stops while speed comping which are similar to what was going on when I was testing out the Audition feature back in X2. X3 on this system gives me very little trouble as far as engine stops, dropouts and crashes so it's definitely doing something funky.
 
Anyway I guess if this is confirmed I'll post in the Problem Reports section.
 
Thanks.