robert_e_bone
 
1.  When you installed Sonar X3, did you run the installer program with the 'Run As Administrator' option?  Please understand that this is not the same thing as having a user account with Administrator privileges.
... 
Bob Bone
 

I can attest to this: when I first installed X3 I did not install “As an Administrator”.  My default account is in the Administrators group and I realize that these are not the same thing. Nonetheless, I installed without first reading the readme file (will not do that again :( ), which clearly stipulates how to do the installation.  In any case, I started having all kinds of problems, including frequent crashes, even after all of the patches.  Eventually, I uninstalled X3 and reinstalled it.  Everything has been running smoothly since!

I hope this helps. I was having constant instant crashes for a few months and finally solved it through working on a different problem I was having strangely enough. What I noticed, in my case, was it seemed to be the audio driver was causing the crashes because I couldn't even get the program to fully quit after the crash unless I completely rebooted. One day I just unplugged my audio interface and finally got the program to quit. So I figured that's probably where the problem was. What was happening was this. I have a Roland Quad Capture USB interface, however I also use a POD HD guitar processor which also has it's own audio drivers. Somewhere along the way, Sonar switched my routing and was splitting the audio processing between the 2 devices instead of just using the Roland, which is the way it was supposed to be set up. I went into preferences and put everything back to 1 driver for in/out and no more crashes. Do you have more than 1 audio driver on your system? Or did you at one time? Make sure you're only using one. I hope this helps.