Clean iPhone charging port with clean dry toothbrush. Try different know good USB Cable. If still problem, clean iPhone charging port again with toothbrush and small amount of Isopropyl Alcohol. If still problem and there is Warranty or AppleCare, make Genius reservation and take iPhone to Apple for resolution. If no coverage, replace iPhone dock connector assembly.
Are they Apple made wall chargers?
I ask because I have found that my TomTom car doc stopped charging my iPhone 4 and when I went to TomTom's forum I found that many people's TomTom car kit stopped charging after an update to the iPhone iOS.
So it might not just be the TomTom car kit that stopped working after Apple updated their iOS, it could be many non-Apple chargers have failed to work after the update.
I "fixed" mt TomTom car dock. I had to look vary closely in the port on the iPhone to see that dust, (pocket lint?) had built up and gotten compacted, preventing the plug from seating properly.
I noticed that ANY charger cable that I plugged into my iPhone was sitting crooked. It would charge, so I didn't think too much about it.
Then I took a look in the slot in the bottom of the iPhone. It looked dusty. I took a wooden tooth pick ane started pulling pocket lint out. I swear I got a bushel basket of lint out.
Now, not only do the charging cables seat squarely, they go all the way in, not just half way.
And the dock once again works. I can charge, use the navigation app and play iTunes through the dock.