Hi,
* Are you sure that the PIC is running at the desired frequency? You DEFINE OSC 4 but is it actually running at the 4MHz?
* Have you doublechecked the schematic and circuit? Do you have the RX/TX pins wired properly?
* I'm not 100% sure it's needed but I don't see any TRIS settings for the TX/RX pins, when in doubt do it, TX is output, RX is input.
* I don't know which PIC you're using (which PIC are you using?) but are there by any chance any analog functions on the TX/RX pins?
* What is LCD_D.bas?
* Do you have a scope or logic analyzer you can use to verify that the PIC and/or PC is actually sending something and that the baudrate is correct?

/Henrik.