Re: Can anyone verify if they are having compass issues.
FWIW, I bought my G3 from AT&T on September 15th, and everything worked flawlessly on it, except the compass. Both my compass app and Google Sky Map were having issues. Specifically, the compass heading was off by 180 degrees initially, and would often be locked to a heading, even while I turned it, so that no matter what direction I was facing, it registered as east. The compass app also always reported interference. This also happened on my father-in-law's G3, bought at the same time.
So, I did the recommended calibration that the compass app suggested, which is to walk in a figure 8 a few times. That did not solve the problem by itself, but what did solve the problem was to do a figure 8 calibration, while in the compass app, and then reboot. After the reboot, both phones have compasses that are properly calibrated, and the compass apps, and Google Sky Map both work flawlessly on both of the phones, and have for the past week and a half.
I use Google Sky Map and the compass application, as well as the GPS every day, and after the procedure I outlined above, they have all worked flawlessly. It appears to me, that LG may not have done an initial calibration at the factory, and that is why a lot of folks have this issue. And that would also explain why others have reported fixing it by using the calibration option in the settings (I never got to the point where I needed to try that), and why I was able to fix it the way I did. But that is just conjecture on my part. Good luck!