I have just got an Etrex 30 and along with City Navigation Europe I have a couple of pieces of Birds Eye France. I want to remove Birds Eye for a short while. Either that or disable it so I can use the City Nav to see what it is realy like. Can it be disabled or temporarily removed?
I don't have an eTrex 30 but my Oregon 450 is similar and you can disable Birdseye imagery.
I don't know the menu structure of the eTrex 30 but if you go to the Setup menu and then Maps you should be able to disable/enable map products and Birdseye images.