Before I Drive Myself Nuts!!

[pwdrive]

Hi Rob, if the problem is on the neutral side then according to the manual the thermistor will not make any difference, maybe time to check that switch again, refer to the diagram that David posted, the switch you have should be a DPST (double pole single throw) one pole and its ascociated contact is isolated from the other pole and it's ascociated contact ie two seperate switches actuated by one insulated mechanism, determine each set of contacts with your avo set to R and mark them or draw a simple plan view and mark the plan. You need to mark them as live in and live out on one set of contacts and neutral in and neutral out on the other set of contacts.

Lawrence.