I have successfully penetrated my D-Link 'N' router with reaver-1.4 in 8 hours. For the record, I had a complex 14 character key, WPS was disabled on the AP and I was using 2.4GHz Celeron. I read that a person experienced a problem similar to yours after successfully resolving a key. Check your settings to make sure that each pentest is properly flushed. Which package did you use? Did you 'make' and 'install' in one line or two subsequent lines like so: (make) then (make install)?