OK, I still don't understand it, but I found a solution to my problem - and Dwayne got it.

At 300 and 1200 baud I would transmit a byte (ex. 11000101) and the PIC would see the same byte but with bit 7 inverted (01000101).

The solution was to go to 2400 baud. Everything then worked like a charm.

I suppose this can be attributed to the bit-banging of the data within the PIC, but I still don't understand why a faster data rate would be more stable than a slow one.

Anyhow, thanks Dwayne and everyone else for helping. I can't tell you how much I appreciate it!

Jeff