I tried to start your distance sensor example and get this error:
NewPing/NewPing.cpp.o: In function
__vector_41': xyz/Documents/Arduino/libraries/NewPing/NewPing.cpp:212: multiple definition of__vector_41'
MySensors/utility/MsTimer2.cpp.o:xyz/Documents/Arduino/libraries/MySensors/utility/MsTimer2.cpp:191: first defined here
I commented everything with "timer" in NewPing.h and NewPing.cpp, but then the method gw.sleep(x) doesn't work well ... arduino freezed