Great explanation Henrik, thanks. Sounds absolutely logical. Unfortunately... still not working.

I've modified the code to look for 65 as you suggested (see below). When I type #65#49#49 (49 would be ASCII for the number 1 which I'd like loaded into each of the variables, though for this exercise it obviously doesn't matter much) I see A11 in the loopback window. But... nothing happening on the PIC. Hmmmm.....

Code:
INCLUDE "bs2defs.bas"relay   VAR	b3 'relay number storage variable
stat    VAR	b4 'relay status ON/OFF variable
serpin  VAR	porta.4 'serial input pin
trisa 	=	%00010000
trisb 	=	%00000000


High 0
pause 100
Low 0
Pause 200
High 0
Pause 300
Low 0


loop:
  SERIN serpin,N2400,[65],relay,stat 'serial data in on PortA.4
  High 0
  pause 500
  low 0
  pause 200
  high 0
  pause 500
  low 0
  GOTO loop