iPhone 4 bizarre charging problem

[drumbear]

My iPhone 4, which is 18 months old, will sync with my macbook and will charge to 10% if I let it go completely dead. When it hits 10% battery OS5 starts up and says "charging is not supported with this accessory" so he battery dies again and I start over. I've done a factory reset, a restore, tried numerous cables that work with other iPhones, iPods and iPads. I even took it to the Apple store where the "genius" cleaned it but it still doesn't work. He said some of the pins have a green tinge on them which he's never seen before. I suspect its a software issue since this happened after I installed OS5 and it will charge, just not fully. He said my options are to either wait until Apple recognise there's a problem with OS5 and fix the bug or just buy another handset for £119. Has anyone ever heard of anything like this before or have any advice?