IFI's website says you have to use MPLAB ver 7.20 and C18 Compiler ver 2.40 (
http://www.ifirobotics.com/rc.shtml). You can find an educational version of the compiler and MPLAB 7.2 is out there somewhere. I was able to get the system working for myself a couple months ago. If you need a hand, or a ZIP of MPLAB and the complier, let me know