There are a lot of old wives tales about pine causing massive creosote build up and hence chimney fires. To hear some folks tell it, burning any pine in your fireplace or woodstove is just about suicide.
Hogwash. Pine is the most burned wood in North America (since it's the most plentiful), and careful studies at a university recently proved it doesn't produce any more creosote than other woods.
Of course, a good hot fire takes care of creosote anyway...