I also would open the machine and see if the wiring is firmly seated on that pad, but I do this a lot. If you don't want to open it or its under a warranty, just use another mouse.
My Touch Pad is not working. Suddenly it just stopped. I have a Toshiba A75-S206 Pentium 4 and it's barely new. Please help me, I''ve already downloaded the controller again and nothing. Your help is greatly appreciated. I'm in south America and desperate.