Craig, it isn't that the transport doesn't start/stop playing when pressing SB. It does every time. It is that not all tracks start playing back correctly when playback starts. Very often I need to start/stop a few times before all tracks will play back properly.
 
I have changed audio buffer size and MIDI buffer size many times but it doesn't seem to make any difference.
 

sharke
...
Every now and then, I will unsolo something (audio, MIDI whatever) and it will send some seemingly random MIDI notes to a completely unrelated synth track. I've never been able to pin it down to the point where I could file a bug report, however.

 
Yes this happens too. Sometimes everything will happily play back, and I select a MIDI track so I can start playing into it from my MIDI keyboard, and then it is as if there is a brief moment where there is crosstalk between many tracks. Very loud since all VSTs suddenly respond to MIDI data from other tracks.
 
This stuff is so difficult to document which is why is isn't easy to file reports on them. In general it just seems that MIDI is very glitchy. For instance one would expect soloing/unsoloing a track while Dim Solo is enabled wouldn't interrupt MIDI data in general, yet it does.

Similar problem: when in speed comp mode with the dim solo button on, sometimes one of the tracks (bass) won't play back.  If I play it back exactly two times outside of speed comping (i.e. hitting the space bar), the bass comes back, and then I can go into speed comping mode and here the bass.  Until the next time I stop and restart the playback, in which case the bass disappears again.  Strange.  

I also find that MIDI tracks sometimes go out of sync when you insert or remove a plugin during playback, especially with ProChannel modules. This can also sometimes affect time-synced effects - if I have a synced tremolo effect on a guitar for example, inserting or deleting an effect will throw it out of time. It's never a show stopper because it's easy enough to stop and start playback, but still these things should not be happening.

That could be due to PDC. Sonar will have to calculate the new delay for all the plugins and sync up everything. That could take time. 

John
That could be due to PDC. Sonar will have to calculate the new delay for all the plugins and sync up everything. That could take time. 

Especially if some plug-ins have lookahead. No way you can put those in without having to re-calculate.

Happens to me often (large projects with lots of VSTi).... usually doing a SAVE fixes it for me for awhile.  Don't ask me, it just does. (I think SAVE might clear out some memory, thus improving keyboard response time - QWERTY keyboard, not MIDI controller).
 
This has been happening to me randomly for years now.
 
Jim

jkleban
Happens to me often (large projects with lots of VSTi).... usually doing a SAVE fixes it for me for awhile.  Don't ask me, it just does. (I think SAVE might clear out some memory, thus improving keyboard response time - QWERTY keyboard, not MIDI controller).
 
This has been happening to me randomly for years now.
 
Jim

The "lots of VSTi/memory" connection sounds interesting. If these are VSTi devices like Kontakt, then a lot of stuff could be loaded into RAM. There can be issues with memory not being released properly. I noticed that dke, whose avatar seems the most unhappy about this , has a system with 8.1 and only 4GB of RAM which is kind of like putting your computer on a starvation diet. However, some of the sigs indicate people with 8 or 32GB having this problem, so it may be a combination of factors.
 
As mentioned, I don't have this problem but if saving fixes it, that would explain why. I save often just as a matter of "computer habit."
 
Whenever a project starts teetering, I'll close the project and re-open. That also seems to quell disturbances in the force. 
 
 

As for another datapoint... Right after opening Sonar and opening a song, I can be almost guaranteed that the very first time I start playback, the transport will move but nothing will play back. I always have to stop/start to get everything to play back.
 
I think this might be related to the issues we had for a long time with MIDI crosstalk etc. Noel fixed bugs in that regard not too long ago but it seems MIDI data is still appearing randomly in the wrong places so maybe there is still some stuff broken in the way MIDI buffers are handled. Just speculating of course.

Anderton

jkleban
Happens to me often (large projects with lots of VSTi).... usually doing a SAVE fixes it for me for awhile.  Don't ask me, it just does. (I think SAVE might clear out some memory, thus improving keyboard response time - QWERTY keyboard, not MIDI controller).
 
This has been happening to me randomly for years now.
 
Jim

The "lots of VSTi/memory" connection sounds interesting. If these are VSTi devices like Kontakt, then a lot of stuff could be loaded into RAM. There can be issues with memory not being released properly. I noticed that dke, whose avatar seems the most unhappy about this , has a system with 8.1 and only 4GB of RAM which is kind of like putting your computer on a starvation diet. However, some of the sigs indicate people with 8 or 32GB having this problem, so it may be a combination of factors.
 
As mentioned, I don't have this problem but if saving fixes it, that would explain why. I save often just as a matter of "computer habit."
 
Whenever a project starts teetering, I'll close the project and re-open. That also seems to quell disturbances in the force. 
 

The projects I typically do are less than 20 tracks with 1 or 2 VSTi's.  I usually have over 50% memory in reserve and Win 8.1  actually uses less than Win7 on my system.  The only thing that used to stretch my systems memory was Melodyne when it Sonar/Melodyne had a problem eating ram and not releasing it.  Since that was fixed in Sonar X2 memory has never been a problem.


I don't know what causes it, and don't really care, I simply stop and restart the project and it's fine after that. I was merely confirming I've seen the OP's problem.
 
Dan

I have never ever had a sync issue either with Sonar since I got rid of my Creative Audigy card. That was the cause of this sort of behavior for me. It would be nice if the OP listed their specs.. 
I have a feeling this is system/ driver related.