Since people started getting their hands on Google's "Jelly-Bean"-powered Nexus 7 tablet I started hearing about problems with the responsiveness and accuracy of the touchscreen display. An uploaded video demonstrates the issue at hand.
Geek.com's Ryan Whitwam, who seems to be having the exact same problem with his 16GB Nexus 7, noted the issue on video.
Whitwam -- along with others I have spoken to -- are putting the issue down to the heat pumped out by the Nvidia Tegra 3 processor. This is because the problem seems to develop after playing games, especially those optimized for the Tegra 3 chip. Games will work the Tegra 3 chip hard, and a game optimized for the platform will push it even harder.
The affected screen area appears to be confined to the top-right of the screen (when held in landscape orientation with the camera on the left). However, in this orientation the Tegra 3 chip would be at the bottom-right of the device, as shown in the teardown images below. Directly under the affected area is the Nexus 7's ample battery back.
Another possible issue could be that the screen is affected by interference from the logic board. ASUS, the Nexus 7 manufacturer, was liberal with the copper foil screening material, but perhaps it isn't enough.
Or perhaps the problem has nothing to do with either heat or interference and is down to a software glitch triggered by using the device?
A temporary way to solve the problem appears to be to turn the device off and then back on again, which seems to recalibrate the screen. However, this fix is only temporary and the problem returns when the device is used.
Hopefully, the problem is software based and can be fixed with a future software update; otherwise Google could be looking at a recall of the affected devices.