On 10.04 I used to be able to click on the power button in the top right and choose "Shut Down..." and it would turn off. I installed 12.04 (not upgraded), and now when I do that it just turns off the screen, and sits there. I've tried waiting for a few hours, but it didn't work. This happens every time and I have to pull out the battery for it to turn off.
I have a Dell Inspiron 1520 and this is what the details section shows in System Settings...
- Memory: 3.9 GiB
- Processor: Intel® Core™2 Duo CPU T7500 @ 2.20GHz × 2
- Graphis: Unknown
- OS type: 32-bit
- Disk: 78.9 GB