Hello All,
Without seeing a complete schematic:
Be careful as to how much current you are trying to sink!
Please place a 330 ohm 1/2 watt resistor this limits the current that the pic output is switching to 15 ma. Or use a 200 ohm 1/2 watt to limit current to 25 ma, the MAXIMUM that the pin is rated for.

Just a thought,

Terry K9HA