I'm working with a pair of Dell U2410 monitors and an AMD Radeon HD 7700 combo DVI/VGA card. Something is making Sonar Platinum crash, and often, and this is really only since I updated the video drivers. I'm suspecting Catalyst (never had much luck with this software, ever... Catalyst's HDMI audio driver is not installed.). All I have to do is click on anything while transport is underway, and it just freezes the screen. Not every time, but often enough to stymie creativity.
 
I've tried stretching my view across both monitors (looks great!), or undocking the Control Panel to my second monitor. Crashes happen more often stretched, but they always happen.
 
No other software on my PC will cause a crash. Not Adobe CS6, not games, not browsers. Only Sonar crashes. I've looked at event reports (Win7 64bit), and sometimes it looks like GTR5 might be at fault, but not consistently.
 
Would it help if this card was swapped for a dual DVI? Is that what is going on, or can you suggest something else?

I can't speak to it directly but VGA is analog. FWIW I have used DVI and HDMI together, and they worked flawlessly.

I haven't had success trying the HDMI connection, but might explore that again.
 
I'll be gone most of the day, so will be checking this as I can.

Just make sure to disable any HDMI audio crapola(well it is to US).

Running 4 monitors with 2 cards, mix of vga, hdmi and dvi. All good.

I can make this happen by switching the master power off and on to a set of track filters while the track is playing. Specifically BT Stereo Imager and VT-64 Vocal Strip, on an otherwise simple track with a single short bit of audio. It won't happen every time I do this, but it happens. The audio will continue to play, but the transport is frozen, and eventually Sonar has to be closed.
 
Another way to crash it is to put a window over Sonar, say my browser for instance. If I put it up over monitor 1, when I close it Sonar is a blank white screen and has to be closed. This will happen whether the transport is moving or not.

So I have uninstalled all the Catalyst software, and it still crashes.
 
Next I turned off looping... so far no crashes.

 
Here is what I see when there is a crash. The second box called HUDNowTimeFB will not pop up, but this is what happens.
 
The filters in place are these:
 
GTR Tool Rack (3.5... likely culprit?)
Izotope Alloy 2
BT Limiter LM-2S
BT Compressonr BT-2S
BIAS
BT Stereo Imager
VT-64 Vocal Strip
 

Something I had been overlooking came to the fore today. I decided to try removing VST instruments and see what that did. Removing effects had not brought good results, so why not...
 
Ivory II had been causing weird problems lately (especially the Cantabile standalone keyboard), so I tried it first. That was the problem. Simply replacing the synth with Addictive Keys demo resolved everything. I can click, drag, maximize, minimize, throw up other windows, let it loop... nothing makes it crash anymore.
 
I loved Ivory II, but not so much as to let this go on.