proteus not working with pic interrupt

[newnew]

i made a simple circuit ,
pic16f628a
lcd 16x2


every time i signal RB0 interrupt happen and it count on the lcd
the circuit works in real. everything is ok
when i simulate it on proteus

the lcd works but the counter is not showing as if there is no interrupt

any idea if i have to set something for proteus to simulate interrupts ??

thanks