Hi, Joe.
We are using dual bias, but just negative 12Vdc consumes much much more current. I Think that +12Vdc current consumption may be normal.
We checked biasing connection before testing, and each bias pin (Vss and Vdd) connected correctly.
-12V power supply is connected to the Vss pin and we checked the current displayed in the power supply.
We tested about 30 switches, and got the same result.
Thanks,
freewill