Is that really the BIT that you want to test? (i.e. 0x00 != 0x01)
Did you clear the interupt before you enabled it?
Did you clear the interupt in the ISR?

Be careful of the following bit toggling tricks...
	-instead of setting the value in PORTX, you toggle TRISX
	-this seems to work in some cases but if it fails, it will cause
	 much pain and suffering
	-sometimes it is better to write a little more code and to have it
	 work for sure
	-this issue has come up when porting code from 16F84 to 16F877