[Joe Ross]

Is it possible that what you are seeing is inverted from what you want? In the RS232 spec, 1 is -3 to -25 volts and 0 is +3 to +25 volts. However, for TTL serial ports there is no standard. In some +5v is 1 (as normal ttl) and in others 0v is 1 (taking the lower votage as 1, like RS232). Some microprocessors have settings for standard and inverted serial ports, I don't know if the PIC has that, or if the other device you are interfacing with does.