Some strange stuff: under openbox session, tilda’s transparency works. Under kde, with kwin, tilda it is also transparent, but if I use openbox as windowmanager in kde4, there is no transparency for tilda. Somebody knows why?
(by tilda, I mean the quake like, drop down terminal )
I don’t have an answer to your post.
Better use yakuake instead of tilda under KDE.
I use Tilda because it can be set to appear in taskbar and in alt-tab list, so I can switch easy from tilda and back. It is easier than pressing F12 like mad to bring to front Yakuake, at least for me.