Did you have that rear door open when you were trying? There's an interlock plunger with a white head that's visible when you open the door; it keeps the seatback from ever going forward with the door shut. If the door was open, perhaps this interlock is sticking? I suggest that you open both rear doors and compare the positions of these interlocks-I bet that's your problem.
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car