The -dhsmall matter versus pixiedust versus brute forcing WPS locked routers is addressed in the help file. Note if you retest 12345670 every X cycles reaver checks this pin with no --dhsmall thus sending complete Pixiedust data sequences for pixie1.1 to test. It also writes the session to a different file and folder so the brute force sequences are not upset. Again read the help files this matter is addressed there in detail.
We have never had any problems that rqr -C except when the wifi device didnot support packet injection.
