Just got my G2 and neither included sim card will connect steadily.  It did intermittently connect long enough to get the new firmware.  I went into the local store and they are in the process of returning a batch of G2, seems like a recall.  Works great on wifi.  Either way, anyone else experience sim card issues?  I tried the trick of putting tape on the back end of the sim card so it presses on the contacts better, but that didn't solve the problem.  Also swapped from Global to LTE/CDMA and that didn't help either.