So I get the gig machine out. Get it all setup. Boot Windows, load Hoster, and guess what...no issues.
Now I really don't know what to think. I've started other applications, played videos in OtsDJ. Come back to Hoster...running fine. No lag, key change working fine, searches are as fast as ever.
So now I'm concerned about what to do at the next gig when it happens again.
Since I can't determine the root cause or find a definite resolution, I'm left with a big question mark in my mind. 
The one thing I wasn't able to do last night at the gig was reboot. I shut down and restarted Hoster a number of times without any change. Maybe a reboot would have fixed it. Buy why?
And how do you gracefully go about rebooting your machine after the show has started?
I really love using Hoster and have impressed many people over the years with it. But this uncertainty is enough to give me an ulcer. 
Guess I'll just keep my fingers crossed that this was a fluke.