I was confounded by the failure of the escape ESC key using Excel intermittently. Through a search I finally discovered that Photoshop Elements (and apparently other versions of Photoshop) run some other service that causes this side effect. I found this was reproducible. So if your ESC key stops working, check out what else you're running.

Discussion here.

http://answers.microsoft.com/en-us/o...5-e6b980782262