Did you download it with your Blackberry Browser set to emulate Blackberry? Emulating something else is the most common cause of Google Map problems. It fools Google into sending the wrong software for your device.
As far as the GPS, do you have BBMaps installed? If so, run it, go to Menu/Options/GPS Settings and set your internal GPS as the source, then see if it works.
Have you just gotten a new 7100i? Are you sure you have a data plan? If you just got the phone today, it might not be fully activated yet. Can you log on to Sprint's site and resend your service books?