Thomas,

No expert here, but you probably want a current limiting resistor between the PIC output (C6) and the PC. Otherwise the PIC is trying to pull-down the 'iddle' level (which I believe to be +12V) to ground (not a good idea). The manual (PBP) suggests 1k in series, I have used this with many other PICs before and it has worked with no problems. SEROUT2 assumes 4MHz clock, which is what you're using, so you should have no problem there. Is the C6 output an open-drain, or analog type (I do not have the datasheet available). If so, you have to use either a pullup or define it as a digital IO (whichever the case may be).

Good luck,

languer.