I've had my Nexus 7 for over a month and a half now. I bought it at Staples here in Canada. It was working great and I was really enjoying the device.
Then, yesterday, it just stopped to auto-rotate. And it's not only the homepage. Unless an app forces itself in portrait or landscape, it won't rotate. This applies to Chrome, Youtube, the stock Transformers movie, the stock Book, every app. When trying to play a race game that need the device to rotate in order to turn, the car just slams itself into the left wall right from the start. I also noticed the "Compass" app doesn't find the North and that I need two full turns on myself for it to finally hit South (and it's wrong of course) !
I double checked that the auto-rotate in Settings > Accessibility was checked. I toggled it a few times. I rebooted the device many times. I also performed a Factory Reset. The problem is still there.
I tried another launcher (Apex Launcher), no results. I can set it to either Portrait or Landscape but no auto-rotate.
I also tried the Ultimate Rotation Control trial app, same results as with the third-party launcher.
I tried a calibration in "Compass" app by doing eight's with the device, no results.
Finally I tried an accelerometer app but I have difficulties to understand the readings.
I don't know what else to try before calling it an hardware problem and going after Asus for a replacement since it's more than 15 days old. If you have any suggestions or if you also experienced this problem, let me know.