Nope mate it's picky what it works with, it wouldn't accept my 3Gs but was ok with my early iPod nano fink it was a gen 3 ?
Some wont actually fit in to the dock anyway. You can buy something called a jive 2 if I recall correctly it carries out the pin swap between older and newer devices plus its cabled so it means it doesn't dock direct either.
I've not actually used this myself but I looked in to it prior to installing MDI
