If it works with a different adapter then most likey a faulty adapter and not the phone...
Even after closing out the few apps I had open the "charged" icon remained. I had to physically unplug and re plug to get the charge going again. Not a huge issue but could be a problem if you were not aware of this happening and the phone died while driving and using your navigation.
I am having the same problem with my phone charger, but instead its the cord that isn't working., i have to sit and fiddle, shake the cord until it says charging then i have to sit it in the same spot without moving it until its charged. I rang telstra to have a new one sent and they said the only way they could do this was if i gave them my charger and they sent it away to be "fix", that would mean i would be without a phone for over a week? what is the point of paying so much insurance ontop of my plan if nothing works and can't be replaced? I can even get over to the telstra shop to send my cord away, i live in a different down and had to take time off work to be able to pick my phone up, even then it didn't complete its set up so i had to go back over the next day to get it!!.
I actually found another discussion, and several people have been having the same issue. They've fixed their problem by just getting a whole new charger and cable. So I'm guessing there just have been dodgy chargers/cables. I really hope that's just the problem in my case. But I'm glad I can still charge it through my computer, because I need my phone daily. Will be going into Optus tomorrow and hopefully they give me a new charger on the spot!