Parallels Desktop process has 100% cpu *after* closing Windows 7 vm (OSX 10.10, Parallels 10.1.1)

I've read the http://kb.parallels.com/en/122767 (but, I'm not using an iMac) and http://kb.parallels.com/116263 (which I have done - it did stop some CPU racing that I noticed while using my vm) However, I'm seeing something different, and I'm wondering if it could be related.

For clarity, I'm using a Mac Mini 5.1 (Mid 2011), OSX Yosemite v10.10, and Parallels 10.1.1 with a Windows 7 vm.

What I find is that *sometimes* (not every time) that I close my Windows 7 vm, the virtual machine process finishes just fine (the process is no longer visible in the Mac Activity Monitor). Then, the 'Parallels Desktop' process pegs a cpu at 100% and the Parallels desktop app becomes unresponsive. I have to manually kill the task (I use 'Force Quit...', not a kill command from the terminal app). Is it possible that I've encountered a different 'interrupt storm' - or is it not possible since is not the vm process using the cpu cycles? Is there a process I can follow to diagnose what's going on?

 

Update: it seems like this can also happen after I try to close the Parallels app. So, the VM will close and quit, then the 'Parallels Desktop' app will be fine, until I try to quit the app. Then it starts to race the CPU and becomes unresponsive.

Just in case that helps with diagnosis or if someone else sees that symptom.