VST instruments windows closing.....

… upon opening their channel setting in the mixer. Does anybody know how to disable this? I cant for the bare of me understand why Steinberg have made this feature. I have searced the net, the manual and this forum but I cant find anything on this topic. Is it just my system or is it a known problem/feature? Anyway, to me it`s just a stupid feature that I would like to get rid of. Any help appreciated.
EastM