PICKIT 2 Debugging, why is PIC stuck in reset?

Unfortunately not, what i've found is that (for this program alone) it will only debug on the occasion immediately after i have 'fixed' the target with another one of the codes i have written, then overwrite it with the one i am trying to debug now.

I have no clue where to look next, none of my other projects have had this problem, as a relative novice i'm out of ideas.

It seems as if the memory is not completely clear and that is hindering the operation of the micro,
i went to debugger>clear memory> all memory

then proceeded to re-download the program onto the chip.
It seems to be working fine now.. just wondering how long it will last