He's referring to this page:
This circuit:
@OP: don't make people work too hard to help you. Give them some links and clues about what you are asking.
Ive gone through the pain of discovering i had to go back to IDE version 0023 to get it to upload
It was written a while ago. I deleted the first line of the example sketch, namely:
#include "WConstants.h"
Then it compiled OK under version 1.0.1 of the IDE.
How about posting the actual master and slave sketch you are trying? You should be able to get them both to compile under 1.0.1 using the method I described above.