I mentioned this before WRT Dragon naturallyspeaking, but it seems to be more general. Typing into a seamless (unity) window can be disrupted by a shift in window focus, or a repeated (~x6) of a key press. The host is linux mint 64, mate desktop, emerald windows manager; the guest is win7-64 with all the updated patches. The unity window banner color changes from foreground to background, and keyboard and other input (voice) goes elsewhere. The mouse click refocusses properly, but just that and temporarily.
This is with the latest TP:e.x.p build-790308.