Try updating, they just released a new version of ASIO4ALL actually.
 
 

Old thread alert. John I suggest a new thread and not ASIO4ALL. Ta

It sounds like you may have 32-bit plugins loaded into a 64-bit Sonar project.
 
This causes a piece of bridging software, called BitBridge, to get loaded, and sometimes this continues to hang out in memory for a while after exiting Sonar, and may leave Sonar in memory too, if memory serves.
 
3rd-party 32-bit plugins can be problematic in 64-bit Sonar.
 
Bob Bone

Whoah good catch Alex! I read that whole darned thing and just piled on. Sorry!

My reply was to the 3-hour old post by jJohnbee58, not to the OP.
 
Bob Bone
 

Go into the control panel and try disabling and re-enabling your sound card driver. That may allow Sonar to close.
 
If this works, make a shortcut on your desktop so you can get to it easier. 

Confusion every time LOL .

IN MY CASE - Re-installing ASIO4All fixed this problem. IF You have asio4all Try uninstalling it and then re-install it.
 
if you know how, dump the process and run a windows debugging session over it and see if the stack looks similar to mine
 
 

Another reason why you shouldn't piggy back on a thread. The new poster hasn't stated they are running ASIO4ALL at all. Hopefully they have avoided it. I'm worried they may end up installing it in the confusion.

Please can the new poster start a new thread before more confusion spreads, this sort of thing needs to be troubleshooted on a person by person basis.... Thanks...(BTW Bob has the best suggestion so far).

Yea, sometimes SONAR midi shows up in the taskbar/hidden icons.  I can restart SONAR when it doesn't shut down properly, then close it, and problem is solved.