dke
 
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.

 
Wow, I'd like to know how you get away with that! I have a laptop with 4GB of RAM and according to the Windows performance monitor, it uses 50% of its memory just to wake up in the morning, make coffee, and run an instance of Chrome. I've disabled just about all the background processes. If I open Sonar and one instance of Dim Pro, it hits 65%.

Anderton

dke
 
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.

 
Wow, I'd like to know how you get away with that! I have a laptop with 4GB of RAM and according to the Windows performance monitor, it uses 50% of its memory just to wake up in the morning, make coffee, and run an instance of Chrome. I've disabled just about all the background processes. If I open Sonar and one instance of Dim Pro, it hits 65%.

Before loading a project in Sonar my system is at 28% memory usage. After loading the current project I'm working on that uses 19 tracks (+ 3 unused archived tracks) with one being a VSTi I'm at 53% which includes IE running. 4 instances of GR 5, 1 AD2, Ozone 4, some reverbs and prochannel. I've rarely gotten up around 75% or so when using Melodyne.
 
I've done very little tweaking on my system and it works very well.  I've been waiting for my system to take a dump so I can buy a new one, but it just keeps on going, going, going...  going on 8 years now. :)
 
Dan

Guess it's time to dump the Vista-64 laptop, but it just keeps going, going, going...

johnnyV
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.

I've had this same issue across at least my last 3 systems, each having completely different specs and different audio interfaces, so I honestly don't think this is related to system or drivers. Why would a driver cause Sonar to play some tracks properly but not others? All of this is mixed inside Sonar before any driver ever sees the data.
 
BTW this issue seems to be related to how complex the project is. Simple projects don't seem to reproduce this issue. The more MIDI tracks you have (especially VSTis sending MIDI data out), the more likely it will reproduce.
 
Another data point: I froze a vocal track, and simply muting/unmuting this frozen vocal track while playing back will interrupt MIDI playback on pretty much all other tracks. Doesn't make sense but it happens every time.

SilkTone
 
BTW this issue seems to be related to how complex the project is. Simple projects don't seem to reproduce this issue. The more MIDI tracks you have (especially VSTis sending MIDI data out), the more likely it will reproduce.
 

This seems to be true for me in a lot of ways, in that the larger and more complex synth-based projects get, the more oddities they seem to develop. I've had to abandon more than one project and reconstruct it from scratch because all sorts of weird things started happening. 

I'm trying to do a video capture to demonstrate the issue, however I'm having problems. Maybe someone can give some tips on how to do this.
 
I installed CamStudio, so I'm trying to capture the video and audio but that is failing. For one thing, it doesn't seem to work with ASIO (yes, I know. However I found it gives me the best results). So I tried all other driver modes with no luck.
 
I also sometimes get a popup with this error when I start recording:
 

WaveoutGetSelectControl() failed.

 
Any advice on what worked well for others?

Ok this is a pretty old thread now but since I finally got around to making the promised video of the problem, and some people didn't understand the problem or didn't believe it, here is the video:
 
http://youtu.be/M5av9ppI4vw
 
It was confirmed that the new SONAR still has this same problem in this thread. I must say I'm baffled why such basic functionality is still broken in SONAR year after year. SONAR has its roots in "Cakewalk", which was a MIDI sequencer that didn't even have any audio capability at the time, so one would think its MIDI implementation would be rock solid at this point.
 
I guess the next course of action would be to wait until I can get SONAR Platinum and make a new video showing the issue, and use that to file a new problem report.

I tried your project in X3d demo version, routed all midi tracks to Cakewalk sound center and I can confirm the bug. Sometimes it was completr silence I got after cycling Solo button but usually I got only quick "tss" sound every time the Now time marker was passing starts of midi notes... i remeber having this issue in X1 as well...

 EDIT: Brain fart, one should learn to read properly.

Anderton

dke
 
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.

 
Wow, I'd like to know how you get away with that! I have a laptop with 4GB of RAM and according to the Windows performance monitor, it uses 50% of its memory just to wake up in the morning, make coffee, and run an instance of Chrome. I've disabled just about all the background processes. If I open Sonar and one instance of Dim Pro, it hits 65%.

My Internet/travel laptop I'm typing from now is using 1.01Gb with Firefox open. There are some services relating to random stuff running too, scanner, drawing tablet etc. I have 2gb in this. This is a Windows 7 starter machine.
 
I don't recall it being much more in my old Vista 32bit 3GB laptop either. Are you sure something is not quite right there?