I sometimes use the orchestration program Miroslav Philharmonik by IK Multimedia with Sonar X3.  I find that when I do use it, if I load more than 2 instances of it (I use 1 instance per instrument), after I save the project and get out of it, when I go back into it I'm locked out.  The project will not open and Sonar will crash, at least on that project. 
What could be causing this?  Does anybody else have this kind of issue with this, or any other plugin when used with Sonar?
 
Thanks
 
John B

I don't know the cause, but the obvious suggestion is to learn to use it multitimbrally.  It can handle 16 parts.  Seems a waste to run a whole instance per part...