I fixed tonight a problem with rfrpi and Raspberry 2+ ; it seems that wiringPi 2.25 have a bug with delayMicroseconds() function that works perfectly when less than 99us and do not work correctly with larger values.

Waiting for the fix the code have been updated to work correctly with RPI2+ ; so please if you are using the shield with RPI2+, update the rfrpi code from bitbucket.