Is it softmodded?
Games aren't reliant on sm but it would be advised to update to 4.1.
4.2 and 4.3 sm's were brought out purely to kill any hb you may have installed on your wii.
Mauifrogs mod any wii guide will softmod you and also upgrade you to 4.1 if on a lower system menu or if you are on 4.3 you can downgrade.
There is a ios update pack in the guide as well which will give you the latest ios's if you wish to play a newer original game through the disc channel.
When using a usb loader the games is loaded through your cios and not ios.