I've had 2 charge-related glitches so far; but this is probably out of 30-50 or so so I'm not panicing just yet.
#1 USB cable was secured well enough, and offered the PC USB data connection, but couldn't charge. This was on the same (unloaded) port that I always charge it on as normal, but it just refused to. The charging indicator was on, it just never moved after several hours.
#2 Wall mount charging, the unit crashed/froze overnight on my home screen and couldn't do anything (couldn't even power it off), had to remove the battery. Hadn't even removed the cable yet so it wasn't on a connect/disconnect action.
All the other times using either method has been fine, though 9 times out of 10 (especially since the hard crash) I'm charging through USB to PC cable rather than the wall mount, which suits me fine because I need the unit hooked up to the PC for some hobby development/debugging anyway.