jt25741 - but this is just the problem - this is what I do, and it always reverts back to wifi. I have gigabit ethernet directly connected to the back of the Touch, so no reason whatsoever to ever use wifi on that particular device, but regardless it always tries to connect (and usually succeeds) via wifi before ethernet.
I think you'll find that, next time you power the unit down (for whatever reason) it will go back to wifi on startup. Try it, report back (if you could)?