Fail to write port B RB7 (aurelien)

Hello,I use a PIC24FH64GB002. I manage to write all other bits of port B except RB7. I configured TRISB as digital output (TRISB=0 and AD1PCFG = &1FFF). This pin is shared with INT0 but I don't use any external interruption.Thank if somebody have a so..