You may have other issues to solve but the newer versions of the libraries eliminate the problems with PROGMEM, I'm not sure exactly when this change was made but with 1.5.2 you had to put something like this where ever pgmspace.h was used:
#define PROGMEM /* empty */
#define pgm_read_byte(x) (*(x))
#define pgm_read_word(x) (*(x))
#define pgm_read_float(x) (*(x))
#define PSTR(x) x
1.5.4 has a pgmspace.h set up for the Due with a more comprehensive set of macros, I think 1.5.3 did too but I'm not sure.