Thanks for helping on this Klaus, you are right, the transformation is needed. And one more thing, if the projection is used in this case, the transformation would be very complicated, e.g. in this case, the map unit is Meter, a polygon from trckOverlay lies across the dateline, RectangleShape(0, 1000000, 20137508, -1000000), then it should be converted to decimal degree to execute the spatial query, but the projection cannot convert the coordinates which is out of range, so we have to make it to (0, 1000000, 20037508, -1000000) in our code, and the converted result is (0,8.94657,179.99999,-8.94657), it's very closed to the 180 longitude but never reach. So please notice this when you are doing the transformation.
Regards,
Edgar