Pressure Sensitivity with Trust Tablet

[Scrimshaw]

Using Designer Pro 6 with a Trust TB4200 tablet, I can't get pressure sensitivity to work at all

Tablet hardware definitely supports 512 levels but every time I try to select the default 'pressure' brush profile it first apparently selects then defaults back to the 'non-pressure' uniform thickness profile as soon as the pen makes contact with the tablet. After this the 'pressure' profile becomes disabled and cannot again be selected.

Screenshot is attached to illustrate - Its driving me nuts!

Any thoughts guys and gals?