hi;
if u are using 8279 type of device,a read
from that should remove the interrupt.if the
interrupt status is not getting cleared on read then do this;
org 003h
jmp into_code
int0_code;
;perform ky code read
;wait for int0 to be 1 again
jnb p3.2,$

this shall wait till your int0 staus returns
to logic '1'.
happy learning
pranav