RE: MCC18 .h LATC3, 4, 5 messed up? p18f4550.h
It is worthwile to compare the PIN diagram of the PIC18F4550 to a non-USB MCU. One can see that the pin which belongs to the RC3 bit is used up for the VUSB (that's why the C port has only 7 bit), and the pins RC4, RC5 are shared with USB data signals D+/D-. The latter two pins can also function as digital inputs (digital output is not implemented) therefore RC<5:4> are implemented, but TRIS<5:4> and LATC<5:4> are not.