Pickit 2 debugger stuck in delay loop when used to debug PIC16F877A

My pic microcontroller seems to be stuck in a delay loop when i am debugging using a pickit 2 clone which i bought from a local store. When i use the pickit 2 to program the microcontroller, it works fine but when i use it to debug, it enters the debug session and when it enters the delay loop, it stays stuck there. What can be wrong?