that helped. thanks. i have to rename all the games after the scrape unfortunately... i mean i have to delete endings like "world" "asia" etc.
thanks for your help
@CaffeineFiend: It is actually possible to add the roms directly with the SD card put into your PC but it's not a trivial task. You have to mount the right partition to make it work. Using the browser or the network share in your file browser is the much easier and preferable way to do it.