If you install application from Android Market - remove any previous installed version.
If you install applications not from Android Market, you need to enable "Unknown Sources" in system Settings -> Applications.
At first you need to disconnect your smartphone from computer, because while it's connected and memory card mounted as disk applications can't use memory card.
If you create folders /sdcard/ametro/maps or /sdcard/ametro/import by yourself please check that you don't use a capital letters. Some Android devices a case-sensitive.
Check that /sdcard/ametro/maps contains only *.ametro files, and /sdcard/ametro/import contains only *.pmz
Try to use Refresh menu option in catalog screen.
Try to remove map file from /sdcard/ametro/maps and then reimport or download it, and please contact us. We'll do our best to fix this error.
Update application to new version and reopen aMetro.
At this moment we have station coordinates only for 3 cities - London, Moscow and St. Petersburg, Russia. If you could collect appropriate data (latitude and longtutude of all stations in city - see example here) and send it to us - we will add this information to your city map. Your help will be highly appreciated!
Disable anti-aliasing option in application settings.