Dean,
You may be missing a couple of important function calls that setup the bias transistors for the Idle step. Without these properly configured you won't ever get touch detections. I'm referring to functions:
TSCADCIdleStepConfig();
TSCADCIdleStepAnalogSupplyConfig();
TSCADCIdleStepAnalogGroundConfig();
Refer to the demo code for the necessary arguments for these functions.
-Tyler