Power locks won't lock with button or Keyless?

Hello! I've searched for this in the forums, and came back without anything similar to this problem. Ok, a few days ago, my locks starting locking on their own. That has stopped, but now I cannot lock the doors with the keyless entry fob or by hitting the power lock button (on the drivers and passengers door) from the inside of the rodeo. They will unlock with the power lock button, but will not lock. No sound is made to indicate it is a mechanical issue inside the door. This started two days ago. The vehicle is a 2002 Isuzu Rodeo LS 4x4. Any help would be appreciated.