That may be true. On the other hand, I assume you turn the screen off for a moment to clean it? Turning the screen off temporarily is about the only workaround.
I noticed this happening immediately after installing the Swype Beta last week. Since I don't use it on my Nexus any more, I may try uninstalling it tonight. A LOT of the threads I've read on XDA and the Google bug site mention Swype, so I'm wondering if that might be a contributor...?
I've never had Swype on my N7 and have never played any games on it either. Other than Google's apps, all I have on my N7 is Amazon's book reader, Dolphin browser, and a couple other similar apps that have been around along time and should be stable and compatible. I re-downloaded only these four apps after doing a complete hard-reset/wipe of the device. I still have problems. So I don't think it's any one app that's causing this.