Overloading the of priority queue in stl

I first overloaded () operator in the implementation of dijkstra algo(with priority queue) in the problem http://www.codechef.com/problems/REN2013G. It worked fine but when i tried to overload the greater than operator , it gave WA.
AC solution link:http://www.codechef.com/viewsolution/5646848
Wa solution link:http://www.codechef.com/viewsolution/5646933
Can anybody please clarify if it is a conceptual flaw or concept of overloading has issues with online judges??