Thanks, I downloaded it and tried it, I'm getting one error though. "undefined reference to `timer0_millis'". Is this solvable?
It (timer0_millis) seems to be part of the millis() function call so probably your code or one of the libraries tries to access the value directly (not sure this is the proper way to do it). Due uses a different method so the thing fails. I would prefer someone more knowledgeable on Due to comment but maybe replacing timer0_millis with millis will work.
Probably a good idea to attach the project and any non standard libraries so code can be reviewed.
The problem is with the SM library and this code
//save som time by reading variable directly
extern volatile unsigned long timer0_millis;
Try commenting out the 'extern volatile' line and replacing the references to timer0_millis with millis() in the same SM.h file.
return timer0_millis - Mark;
return millis() - Mark;
You may need to restart the IDE after making changes but for me the code now compiles though this is no guarantee it will work.