Hello,
It is not entirely clear what you are hoping to achieve. You appear to have set up the KBI module so that PTA4 should cause an interrupt to occur on a negative edge, presumably when the button is pressed. It then seems you intend to disable the KBI interrupt (for a period of 30ms ??). Whether or not you would get a further interrupt when the button is released would depend on KBI interrupt being re-enabled, and whether there was any contact bounce on release. If no bounce, no interrupt since a negative edge remains selected.
However, there seems to be another problem with your posted code - should not the KBI module use vector 22, rather than vector 3?
Regards,
Mac