Thanks Bob for your settings recommendation but I have the same settings, and until then, no major problem ! (Except sometimes some incidental and intermittent freeze and crashes and in particular, with the Plug-in PSP master comp (inserted in a mono track) which made inevitably crash Sonar X2. just a week ago, I upgaded to X3). Concerning recording, I always record "dry" without effect...
Concerning the incriminated project, this just around 20 tracks of pre-recorded wave clips and some loops; no virtual instruments, and when I mute a track, I always deactivate the effect...
 
Thanks brundlefly for the confirmation !
 
Bitflipper, thanks very much for the advice, but I've already checked the Windows' Sound and Audio Devices control panel applet, and it seems everything is in order.
What it is odd is that the disorder is just caused by this project (which have Soundtoys and Waves plugins, but maybe, it's got nothing to do with the problem) and it's always the same scheme : once this project closed, I have the message : Sonar stopped to work, and after, every project I open, The audio driver are missing. But I haven't checked if at this precise moment, the audio devices and drivers are present in the Windows panel (?). In any case, when I reboot my system, everything is OK, except until I open this particular project.
I should uninstall and reinstall the drivers but I intuited that there is something else, because, in my humble opinion, the other projects would have similar problems.

Have you tried putting those plugins into a new project, to see if the combination produces similar errors?
 
Bob Bone
 

Hey Bob,
Yes exactly, I'm trying another project with the Soundtoys plugs (Microshift, Decapitator, and Echoboy) : Until now, everything is ok. I noticed these plugs are "heavier" than the average, all the same and there are some slowness and strangeness concerning GUI display. I just remember that in the "mad" project, I made quick test by changing the original tempo (I passed from 95 bpm to 132 and vice versa) in order to test the tempo synchro of the delay based effects of the Soundtoys on some loops; maybe there is nothing to do with the problem...
 

Are these 32-bit plugins?
 
Do you have the latest published version of these plugins?
 
I found this about Microshift on their web site:
 
"2/18/14 UPDATE: MICROSHIFT IS SUPPORTED AS 32/64-BIT PLUG-IN FOR ALL OF THESE HOSTS. It is our only plug-in that is running in 64-bit VST and AAX for Windows at this time. MicroShift will also work in Cubase on Mavericks."
 
The recent date of this, as well as the statement content, is why I asked about the versions, and about them being 32-bit or 64-bit.
 
If you are using 32-bit plugins in a 64-bit Sonar, then bridging software must be used to allow them to run in a 64-bit host.  Cakewalk includes BitBridge, which may or may not allow a particular plugin to work properly in 64-bit Sonar.  Some folks buy a marketed product called JBridge, which functions in a similar function, and even there some plugins will work and some will still be flakey.
 
So, please review the above and respond, and we will continue to dig into what is happening with this on your system.
 
Bob Bone

Hi Bob,
Thank you very much again for your very appreciated kindness in order to help me !
I've just downloaded the demo version of these plugins few days ago and all the Soundtoys plugs are  in version 4.2 with 64-bit support for Audio Units and Windows VST formats, since August 5, 2013. I'm very careful to work only with 64 bits plugins.
Yesterday, I reported the problem at Cakewalk and Soundtoys, and waiting for their feedback. But I suspect that if I'm alone to have this kind of problem, I'm not sure that they go further...
Thanks again