Problem with MPLAB's toolsuite
The .map file that's part of the bundle you shared shows that the Microchip C30 compiler was used to build this project. Unfortunately I don't see what version of C30, but at least the compiler is known.

c:/program files/microchip/mplab c30/bin/../lib\libpic30-coff.a(crt1.o)
                          (_resetALT)
c:/program files/microchip/mplab c30/bin/../lib\libpic30-coff.a(crt0.o)
                          (_resetPRI)
Program Memory Usage


There's a free version of C30 (no optimization) that can be downloaded and installed from Microchip's website. Give the latest version a try and see what happens.