Erratic Touchpad on Toshiba M50 Notebook

If the touchpad is working fine with the battery and if it is not working with the ac adaptor then in this case u can try with the different ac adaptor and still if it does the same thing then uninstall and resintall the toouchpad driver and restart the computer and still if it does so with the ac adaptor then u need to open the laptop chasis and then u need to fix up the power supply connector in the motherboard where the power supply from the ac adaptor is not getting the adequate response from motherboard.