Ya know ... the same thing used to happen to me.
Long story short ... I had to move my studio in to the basement for reasons beyond my control.
I've spent about 25 - 30 hours mixing, mastering, and mastering a CD last week.
Sonar crashed twice, which I think is great because I gave it one hell of a workout. Funny thing though, it crashed a lot more than that upstairs, and I saw the same problem of it sitting in memory after that crash for a very long time. I used to just reboot.
Now ... since I moved in the basement ... when Sonar crashed those two times, I was able to immediately restart it. The only time that ever happened previously was with X1 Original Release.
The only changes I made were, I moved my system to different outlets, my Yammy's are running through a high end line filter now, and my sound card is plugged in to a different USB port.
Try one of those things maybe?
I'll be scratching my head over this one for a very long time.
Good luck.
After reading markyzno's post, I remember now that both crashes I experienced were Dimension Pro related. So I guess 'technically' Sonar didn't crash, DimPro did.
For those following my saga ... moving to different outlets, filter on the Yammy's, and different USB port didn't help my Pro Channel on/off problem. God I hope X2 fixes that, but then again, how will I know? ;)
*bUb StRuTs AwAy SiNgInG
THIS (not a plug -- sorry Baps)*