Comment 31 for bug 1010981

I am experiencing the same problem in a hp compaq 6720s laptop, ubuntu 12.04 dual boot with win vista:

When laptop on ac adapter, I can shutdown the computer from menu or command line (sudo poweroff ) without any problem,
but when on battery, the laptop doesn't shutdown, it remains in splash screen showing ubuntu logo and dots going from red to white forever, neither trying from command line. Laptop doesn't respond to any combination key : Alt+SysRq RESUIB or CTRL+alt+del. I have to poweroff the computer pressing the turn on/off button