I found the cause of the problem: besides my Unity plugin the Desktop Wall plugin had been disabled as well. Enabling it via CCSM (and ignoring some complaints about conflicting plugin settings involving something like Flip up/down or so) resolved the issue.
I found the cause of the problem: besides my Unity plugin the Desktop Wall plugin had been disabled as well. Enabling it via CCSM (and ignoring some complaints about conflicting plugin settings involving something like Flip up/down or so) resolved the issue.