Here to specify, THIS is what I'm experiencing also, just had a tad different words to use when I was describing the situation.
But PhoneyWar, have you checked the Processes-tab from Task Manager?
I ran a test, as you had described, closed the "Buy Now" window, everything SEEMS normal now, but the "CM Normandy Demo.exe *32" stays on the Processes tab. Also, still using up memory on the Memory (Private Working set) field and CPU field. So this is what I mean, "I'm forced to "End Process" here on the Processes tab.