Have you set up the port defines?
RTFM.
MEL PBP manual page 91 LCDOUT gives a damn good description, shows how to connect it and everything.

UNRELATED to jmgelba's question:

While on the subject of LCDs I keep wondering why people buy and use the serial adaptors for LCDs. Economically speaking, they cost around $20 or so, but a PIC with aditional port lines, say a full port, in a 28 pin version is only in the order of $10 or so. I do think the extra bit of programming experience is most helpful. I used a (few different) serial bacpacks too, until I came across Mel's Olympioc Timer and RTFM It is so much better using the suggested method of driving an LCD and it is easier to stack the LCD module straight onto your PCB or Vero without another backpack getting in the way.