New battery (616-0435) won't charge

Hi,

The old battery in my 3GS wasn't holding charge as long as it should, so I bought a replacement online, but it won't charge!

The original battery was 616-0431 and it charged fine, but the new 616-0435 just shows a plug icon instead of a lightning bolt, and the battery doesn't charge.

I borrowed a known good battery from a friend's 3GS (616-0434) and it also charges just fine, so I know it's not the phone. I tried the 0435 battery in the other iphone and it will not charge in that phone either.

Everyone keeps saying that the 0435 is a universal replacement for all 3GS batteries - but it seems to be the only one that does NOT work for mine.

Do I need to locate a battery with an APN between 0431 and 0434 ?

Is it possible to frankenstien the little circuit board on the bottom of an older battery onto the Li-ion cell from a newer battery ?

Chris