I purchased an f90bt off a forum recently. I installed it and it has a custom startup screen and a custom theme installed. It didnt really bother me too much until I attempted to plug in a gps route. Alabama does not exist in my GPS. I live in alabama so this is a problem. Was this a hack or what? How can I fix this? and how can I change the theme?

take a look at FX3.1 thread to wipe the unit and then maybe look at putting 2011 maps on it. Maybe somebody needed some extra space for customization and pulled some of the states maps out to make space...

With FX3.1 and 2011 NT US/Canada maps and pois, most all of the internal 2gb flash is used, but it should all fit..

I also have a digital speedometer function and the seller said it had other mods. I do not want to lose the digital speedometer, will the FX3.1 delete all the mods?

not sure what this digital speedometer is, but it may just be a speedometer display on the map screen - if thats the case, this is just UI display options (skins) and settings in IGO8 (the nav app used by this series of avic).

There are several discussion on these boards about changing these themes/skins/options.. Also, much of the customization of igo8 applies (which is discussed extensively on many gps boards).