It appears it's my PICKit 3??? I've built another board up that basically just has a crystal, LED and ICSP port does exactly the same thing on there too - so at this stage I'm 11 PICs down and growing fast! It's not something silly like code protect off not being specified in the config is it? Here is my config line:

@ __config _HS_OSC & _MCLRE_OFF & _BODEN_OFF & _WDT_ON & _PWRTE_ON & _LVP_OFF

Thanks