I am using PICBASIC16F776A for an DTMF decoding project.
I am using external interrupt to detect tones ie INT0 pin. If I try to press tones too fast , the program hangs and starts after some delay. Or it just goes out of main execution loop and just interrupt is detected. sometimes program restarts.
Can anyone please help me debug this problem

I have taken precautions with interrupts like resetting the flag at the end of ISR.
I am saving context on interrupt and allowing picbasic to handle memory allocations( so i need not look at paging bits and corresponding context saves)

I would appreciate any helpin debugging this code