I also have the same problem!
Time machine doesn't backup Parallels VM
I'm running Parallels 7 on Mountain Lion an Windows 7
In Parallels, I enable Time Machine backup by:
1. NOT checking "Do not backup virtual machine"
2. SmartGuard option: "Optimize for Time Machine"
But as I look into my Time Machine backup, I can't see the .pvm file in ~/Documents/Parallels (which is its location in my machine). I've tried restarting machine, run multiple Time Machine backups etc. Nothing matters, the VM isn't backed up.
Nobody help us ? 
Please fix quickly this problem !
					 
				
			
			
			
		 
		
		
		
			
			
				Last edited: Aug 25, 2013