no /dev/ttyUSB0

I'm trying to use my Garmin GPSMap60CSx with QlandkarteGT. On Mandriva all works smoothly, however my Mageia does not have a /dev/ttyUSB0 (or any /dev/ttyUSBx nodes as does my Mandriva. I tried creating one using: mknod /dev/ttyUSB0 c 188 0 but it was not recognised by QlandkarteGT. What's missing??