So I want to use pin 4 (RA3) as a switch input pin, I've enabled weak pullups...I measure 5V on there - all seems as it should, but whenever I press a switch (which ground the pin), the PIC resets (I have an Hserout command at the top of my code, so I see the word "reset" only if erhm,....the PIC has reset!)

So I have this as the config.....

Code:
@ __CONFIG _CONFIG1, _FCMEN_OFF & _FOSC_INTOSC & _WDTE_OFF & _MCLRE_OFF & _CP_ON & _IESO_OFF & _BOREN_OFF & _PWRTE_OFF
@ __CONFIG _CONFIG2, _PLLEN_OFF & _STVREN_OFF
I thought the bolded entry allowed me to use pin 4 (RA3) as a normal digital input.

Is there anything else I have to do to stop the PIC barfing just for grounding the MCLR pin?