We see this problem frequently. It sometimes causes intermittent operation or an error code to be displayed.
MODELMany different models of ovens
SYMPTOMSIntermittent operation of oven buttons, sometimes results in a keypad related error code.
Typical membrane connection. This one is a Whirlpool/Kitchenaid model.
PROCEDURECarefully release the locking tabs on the zero-insertion-force connector that holds the keypad ribbon.
Pull lightly on the locking tabs in the direction away from the pcb.
Next check for oxidized contacts on the membrane tail.These contacts on the membrane are oxidized and cause poor electrical connection to the control board.
Clean them with your 2nd grader's Pink Pearl eraser - yet another use for this ubiquitous tool.Here's how it looks after cleaning.

This resulted in a repaired, reliable keypad connection!.
http://www.fixyourboard.com/techzone/ovens/keypad_tail_clean/keypad_tail_clean.html