Got something you might like..... Version 5.0 blocked the ability to do navigation with the basic version. However! 4.5 still works just fine and will do full navigation with no restriction I can see.
If you'd like to load the older version, first remove 5.0 and then do a battery pull if it doesn't prompt you to. Then just download 4.5 OTA and you should be all set.
You can get it from here:
http://hatax.home.comcast.net/bb/amaze/amAzeGps.jad