I do not think it matters if the sound card is USB or firewire . When I had sonar x2 and when I bought platinum , the driver does not unlok after the crash . After i ignored the fault for a few days, things have set for themselves , I can say. Now , after several months of intense work,  I forgot the white screen ... I feel like every time you work on a fresh Sonar renewed strange things happen ... and all this strange behaviour repair themselves in a few days. This happened several times , since the time of sonar 2XL , sonar 7 or x2 ....

karma1959
I used to have this issue a while back after purchasing a new interface (RME UFX), however after multiple conversations with Cakewalk and RME, both parties indicated it was an RME driver issue. 
 
A subsequent RME driver update seemed to resolve it and it's never recurred.  I assume you've got the latest Focusrite drivers?  Have you spoken to Focusrite about it?  That's where I'd focus given my RME experience.

Haven't spoken with Focusrite, but I'm pretty sure I'm just going to sell the unit. It has a separate, other well known issue of causing distorted audio whenever coming out of hibernation/sleep. My VS-100 still works fine and the problem isn't specifically related to its drivers alone.

Hibernation/sleep and power management are Windows activities (and ones Windows has a track record of poor performance with). It is best practice to use neither, regardless of interface. Bear in mind Windows is the middle-man, so any failure affects both ends.

Another byproduct...I also lose the space bar as a start/stop Play function....I click on the Menu Play and it plays, but not with the space bar...the play triangle lights up but no movement.... 

After speaking to Phil Slopak at Cakewalk Tech Support, he had me check a few Windows settings and then make two important tweaks:
 
1. In Preferences, Under Audio/Sync and Caching/File System
        He had me set both Playback I/O and Record I/O to 1024 (the default is 256)
 
2. He had me delete the AUD.INI file in the Platinum Folder (I don't remember the exact location of that file sadly)
 
After restarting the PC and opening Sonar Platinum I noticed one major change. My performance meter now showed 7 individual meters instead of one giant block of a meter. I never noticed that before and it might have been some holdover corruption from updates over the years...
 
I resumed work on a plugin and track intense project with no crashes or problems for 8 hours.
 
I'm not sure which tweak fixed the problem but I am guessing a lot of both....
 
The only new issue is that the snap to function in Midi and track editing is unpredictable...(I'm guessing a preference got blown out with the .ini file) but I can live with that!
 
Kudos and a huge thanks to Phil and Cakewalk!
 
ps I was telling Phil that this was my 1st time calling Tech Support in my 15 years using Cake products!

Thanks Mark! Hopefully this will solve my problems as well!

I've had this same crashing issue for years on every version of Sonar. M-Audio Profire 2626.
 
KEv

Er...Hmm.....Yeah...well I spoke too soon.
 
I had another lockup today after a very long Midi editing session.
 
This time Sonar just froze solid and couldn't be closed in the Task Manager. After rebooting it couldn't open my project, just the spinning icon and a black bar in the time area. After multiple efforts with the same result I was worried I might have lost the file and a couple of days work...opened the project in safe mode and just started over adding back an instrument at a time.
 
I am going to call again tomorrow...very discouraging.... 

Have you tried running a latency monitor tool? I'm using DPC Latency Checker, and I'm averaging around 1,000 microseconds, which is not that great (should be < 500). I'm going to work on cleaning up & tweaking the system to get that number down. Maybe that will resolve the problem?

Are you still running on Ipswich, per your signature?
 
There are Sonar updates available and I am wondering if any of the fixes in those would help.
 
Also, is your Windows maintenance up to current levels?
 
Are there any background services or other applications running that might possibly not get along with Sonar?  Some folks either temporarily suspend their antivirus software just prior to launching Sonar, OR they add the Sonar program and project folder paths to the exclusion list for the antivirus software, and that sometimes help things run smoother.
 
Bob Bone