A personal vibrator that stops when it is touched.

This is a work in progress: The 5v circuit uses an Azoteq IQS127 Proximity Sensor. It uses capacitance to sense touch or proximity. The output of this is a 0-5v level which is fed into the Reset of a 555 timer chip which runs at about 150Hz, 30% duty. This 30% duty 5v signal is fed to the base of a Darlington transistor, which drives the 1.25v vibrator motor.

The Problem:

When the motor is disconnected, the sensor works flawlessly. When the motor is connected, the sensor switches on and off intermittently.

I've tried looping the power wires through a toroid, and this helps, but the intermittent activity is not acceptable. Any ideas on what I can do to improve it?