Battery and charging issues

I have a MacBook mid 2007 2.0Ghz.

When I start the computer and it has finished starting up, I get the X in the battery symbol and it states that no battery is available, yet the battery is in the machine.

The charger is also green at this point too. If I remove the charger, the laptop turns off.

I have replaced the battery connector for a new one. Now when I plug the charger in, the light is orange. The laptop will not start up on the battery alone though. When I start the laptop with the charger connected, it still remains orange and the battery symbol sais it is charging and calculating the time to a full charger. After about 3 mins then charger then goes green again and the X comes back.

I have tried a new aftermarket battery and also the genuine apple battery. I have reset the PRAM and done the power drain with the battery and power disconnected, all to no avail. I have also re-installed the operating system.

Should I be looking at the magsafe connector next, or is there something else going on that I need to try first?

Any help would be appreciated.

Thanks