I have a latitude C610.  whenever i have my computer on with just the AC cord in it's fine.  When i stick a battery in it the cord goes dead (the little green light on the AC adapter just goes out) and it won't charge the battery.  As soon as i take out the battery I can unplug the AC adapter the plug it back in and the laptop's fine.  I bought a new battery and a new power cord, so it must be the laptop.  do i do? add a bios update or something, or get a new hardware peice?