Mediabay Instrument looses preview-volume

When previewing an Instruments’ sound in the Intruments Tab of the MediaBay in the Right Zone, it’s very annoying that the preview-volume-slider doesn’t show the actual Preview-level.
I previewed some audio-files, with the preview-volume-slider halfway, and after that I previewed some Instruments’ Sounds (triggered by a MIDI-note on my keyboard) , also with the preview-volume-slider halfway. Each time when I preview a new Instrument Sound, the preview-volume-slider is there halfway, but each newly-previewed-sound sounds at full volume. I think I know why this happens, but it would be nice if this could be solved.
Thanks.

Niek/ Amsterdam.