mod_proc seems to be working now. I will have to do more testing, but LOCALs such as FATHER seem to work now.
The problem was that when I inserted the code for the LOCALs defined in mod_proc, I had not taken into the account how their values where referred in the DCB (file offsets.h).
This was quite a complex bug in the sense that it would've been very hard for me to find. I have created a modified Makefile so that now I can compile and test most of the code without having to be in front of my Wii.
That helped a bit to find the bug but it was my brother who did most of the debugging this time, so thanks to him :)
So now, only mod_sort, mod_mem and mod_timers are left before I start with the graphical part of Bennu!