It looks for the channel logos in /etc/vdr/plugins/logos/ but the package vdr-channel-logos installs them in /usr/share/vdr/channel-logos/ ln -s /usr/share/vdr/channel-logos/ /etc/vdr/plugins/logos helps. Reproducible: Always
Fixed in vdr-tvonscreen-1.0.141-r2. This version now also has vdr-channel-logos in RDEPEND.