Problems updating Melzi firmware (Nophead's fork)

I am trying to update my Melzi firmware to use Nophead's fork, for my Mendel90 project. When I run the Arduino software that I downloaded from Nophead's link, following the instructions in the Mendel90 build manual as to board type and COM-port settings, I get the following error when it tries to compile:

core.a (main.cpp.o) in function 'main':
C:\Program Files\Arduino\hardware\Melzi\cores\arduino/main.cpp:7: undefined reference to 'setup'
C:\Program Files\Arduino\hardware\Melzi\cores\arduino/main.cpp:10: undefined reference to 'loop'

Why would it be doing this, and what can I do to fix it?

Okay, problem solved - I did not open the "Marlin.ino" file before trying to compile. Sorry, all - I'm still pretty new to this...