I have an HP 530 laptop dual-booting Karmic and XP. This is the series of events that lead to the current state of affairs:

1. Mouse Pad began troubleshooting and acting randomly both in Windows and Ubuntu.

2. As a result, I unplugged the ribbon tape connecting the mousepad to the motherboard and am currently using a USB mouse.

3. Humming sounds can be heard from my laptop during use + while running Ubuntu/windows, the computer randomly shuts off.

4. While using Ubuntu, I run an applet in my AWN dock and realize that the laptop's temperature gets to 70°C easily.

5. I disassemble the laptop (again) with the idea of replacing the thermal grease in the laptop. I find out that the fan is clogged with dust and that the thermal grease on the processor is dried out.

6. Clean the dried grease and put new one in addition to cleaning the fan. Assemble computer.

7. Computer runs fine at about 20°C for some 2 hours or so (in Ubuntu). While playing a video the machine starts doing the humming sound once more.

8. The computer shuts down again.

This is were I currently am. Is this a software issue or a hardware issue? I had run Jaunty on my laptop without problems before so this is very new.

Any help would be welcome.