Sorry if this is already answered, but I already searched this forum and google without getting a answer: how does Mapper build the URL for the tiles?

Background: I'd like to use german maps available from here: http://www.geoserver.nrw.de/GeoOgcWm...COLOR=0xFFFFFF
I tried replacing the coordinates with %.6f but without success.

BTW: Yes, I already installed proj. Did not change anything;-( I am using version 2.4.1 from the repository.

Thanks for any advice

Stephan