3 millions is enough of course.
try with --fcs
also post here what messages you get if you use --debug 1 --debugkey AA:BB:CC
D:EE:
change AA:BB:CC:... with your REAL key (I guess you are trying with your own wireless lan, so you know the real key) and finish with ':'. Post here the lines you get, and we will see why the key does not get cracked
