There's a modified version of reaver call ryreaver-reverse, but i can't make it work in kali debian, only work in backtrack 5rc3 ubuntu.
"and commands are same as normal reaver. as explained this one worked on a station where normal reaver failed. normal reaver got first part of the WPS pin, but failed to get last 3 digits + checksum (last 4 digits in total), but this one did it!"
http://sethioz.com/forum/viewtopic.php?p=9757
Hope someone can figure it out how to make it work in kali, does it have to be compile for debian?