I hope this gets seen...
The solution I had that worked the best for me was this one: https://code.google.com/p/android/issues/detail?id=32633#c21
In the UK 'rubbing alcohol is called surgical spirit.
My issue happened this morning. I pulled the Samsung charger out and got the error popup. Despite rebooting and taking the battery out, it continued. It even flashed up the charging image when turned off.
**NOTE** this may seem obvious to some, but for the love of god take your battery out when doing this and don't put it back in till you're confident the port is dry.
I used a toothbrush with a tiny bit of rubbing alcohol on (after dabbing it on a napkin to remove most of it from the brush) and gently scrubed at the port. The rubbing alcohol doesn't take long to evaporate and you can blow on it slightly to speed up the process.
If you don't feel confident with doing any of this, I'd recommend sending it in for a new one.
I'm going to drain the battery right down today and leave it overnight. I'll let you know if the problem returns, but for now, it's fixed.