Hi Bruce,

Thanks very much. I actually got the same advice from PIC Basic support - although the $72 value was given to me by support earlier, and matched teh value I was using. This does indeed fix it - I see now that the PIC is configured to use the "main oscillator" rather than the internal - but could you please explain why? I was assuming the internal oscillator was everything internal and the main oscillator was an external crystal or RC.

To avoid any confusion to those that may notice - the first OSCCON value I posted had OSCCON=$7F. This was copied/pasted from a file in which I was thoughtlessly monkeying with the values attempting to fix it.