Garmin: missing contour map on etrex 30

[element54]

I'm not able to activate the contours overlay on my Garmin etrex 30. I downloaded today’s Austria map and placed both img files in the "Garmin" folder on my SD card. However on the map activation page on my Garmin it only shows the "base" map. The contours map is missing. Am I doing something wrong? I already tried to shortened the filenames and change the suffix to IMG instead if img. Nothing helps.

Thanks in advance!