You've installed Preloader on 3.4, that's fail I'm afraid.
You need to install IOS50 v4889 and then System Menu v385 both of which you'll find in my Mediafire. That should fix it. Click my image for Mediafire.
After this I would thne install patched IOS60 from 3.1-4.1 tutorial, then run firmware updater 4.1 and then install preloader again. Job done. One working Wii.