bootloader with pic16F819

I seem to only be able to program the pic once using the bootloader. (I think I am not setting up the bootloader program correctly)

I am trying to use pin RA1 for TX, and RA0 for RX
(inverted, using resistors)

I have set adcon1 to 7, to make A register I/O

But how should cmcon be set? And how to you set the enable pin? Receive port/pin and the activation state??

Thanks

If this is in the datasheet, I'd welcome a page reference.


Or, what am I doing wrong?