hi there,

Keyboard and mouse problems could be due to heat..

This sort of problems would appear after some time. Problem could extend from the touch pad to the keyboard.

Easy fixes are suggestion to change the touchpad and or the keyboard.

Just to make sure its not an issue with the OS.

I recommend you down load Knoppix and run it from the CD or USB thumb drive.

If the mouse works fine using Knoppix OS then it would mean you have to check

your current OS. Running Knoppix from a live CD would not mess up any thing on

your system. Every thing runs from the CD and your computer RAM.

Next,

If the external USB mouse works fine. You could disable the touchpad and use it.

Check the ribbon cable which attachs the touchpad to the motherboard.

First you have to get a service manual of your model from the dell site.

The electrical lines on the ribbon cable at the end going into the connector may

have become loose due to heat.

You need to inspect that connetor and reseat it. If that does not help.

Add a piece of  tape to support the ribbon cable a small bit of the tape should

be on the end of the ribbon where it goes into the connector. A smaller layer

of tape at the end would give a good grip at the connector.

Check if there are any kinks on the ribbon cable. Giving support to the cable

is good it will also keep off some heat.

Worst scenario would be to change to the touch pad ..but that is the last thing that I would do.

Let me know how it goes !!!

Atma