OK So the problem persists, and it also occurs with the PICKit 2 software (so it's almost certainly not PICBasic Pro). Ive done some testing and the PICKit 2 dongle seems to fail and remain a problem for a period of time, regardless of whether I reboot, unplug the dongle or whatever. It won't reset and work again until the power is removed, both from the board and the USB cable.

I suspect I have a dud PICKit 2 dongle. It'll take about a week to locate a new one and get it shipped to me (one of the sacrificed of choosing to live in a remote area).

Thanks for all your help BOB

and for information purposes - the DOS windows that open in Windows 7 are for mpasmwin.exe and pk2cmd.exe. These are probably C+ programs used by Microchip.

Kind regards again

John