Igor,

Thank you for pointing me in the good direction. I checked the szap.c from Manu again and noticed that I had to change the declarations of the include files frontend.h and lnb.h (I copied them from the multiproto-tree to the same directory as szap.c). It seems to be that #include <frontend.h> has a different meaning than #include "frontend.h" (I am not familiair with C).

This means for szap.c:
#include "frontend.h"
#include "version.h"
#include "lnb.h"
And for lnb.c:
#include "lnb.h"

This is it. After compiling szap works good and I get a lock for any channel!

Thanks!

Henk