How to build/compile maps with local language?

Hi.
I have downloaded a few countries from http://garmin.openstreetmap.nl/
I download the tiles files (osm_generic_tiles.zip) and then combine the maps using
something like: java -Xmx700m -jar mkgmap.jar --gmapsupp --verbose --transparent sweden/.img norway/.img deuchland/*.img

Looking at the maps on my device, all names are in plain english, any local characters from europe such as:
se: åäö, no/dk: åæø, de: üöä, pl: ąęółśżćź, cz: ěščřžýáí. are all replaced with aeoulrc, etc without their markers.

How should i combine them to preserve the local spelling when i combine maps for many countries at the same time?

Karl

The key issue about maps in different languages is handled in the OSM wiki at http://wiki.openstreetmap.org/wiki/Map_internationalization

But in your case it can be a specific Garmin problem … maybe ask in the Garmin subforum here.