Hi,
The 16F1786 has more than one config register while the 16F690 (and probably the "others" you've tried) doesn't.
Code:
#CONFIG
    __config _CONFIG1, _MCLRE_OFF
#ENDCONFIG
Just remember that when you include a #CONFIG/#ENDCONFIG as above it replaces ALL of the PBP default ones, reverts to the devices specific HARDWARE defaults and THEN sets the bits you include in your block. I usually copy the default PBP ones and the changed/add what I need.

For the 16F1786 the PBP defaults are:
Code:
  #CONFIG
        __config _CONFIG1, _FOSC_INTOSC & _WDTE_ON & _PWRTE_ON &  _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOREN_OFF & _CLKOUTEN_OFF
        __config _CONFIG2, _PLLEN_OFF & _LVP_OFF & _VCAPEN_OFF
  #ENDCONFIG
/Henrik.