That all was either before my time or by the looks of it maybe a PM thing. What if tou used MPASM? Just curious...

Now modedefs seems about the only thing that PBP requires and only for certain command.
But you can still use includes, you are going to love some of the stuff Darrel has done.

Looking at the schematic of the LABx
http://melabs.com/downloads/labx1sch.pdf
What does U2 do? Bad chip?
I am just guessing... as usual