Most find they go back to the old BIOS and a released supported operating system.
I have a DELL XPS M1530, and I have 2 batteries.
last week I decided to try windows 7, and I took the chance and downloaded all the updated drivers, including the BIOS.
Once the computer was working OK, I noticed that my battery level only goes down. it was not charging with the AC power plugged. when the battery was at 0% I thought it was some problem with the battery, So I got my spare one... and happened exactly the same thing.
Now I look at the battery icon on the bottom right, and it says "0% available (Plugged in, not charging)"
do you have any ideia what is going on?