I used the maddog for over 6 months and got good burns with it, but scanning stopped as did bitsetting,
flashed 3 times since then! 2u4 > (Dee's advise) 2u3 > 2u2(MichaelDebor's advise)
http://liggydee.cdfreaks.com/page/3520/
some drives do better with firmware based on 3.05, some with 3.06
course i have 2 more to sort out(3520's)