As on a forum someone pointed out, that with the Heron-Theme, this panel-bug does not occur, I investigated into it and just found some quite simple workaround for that bug:
in the Heron Theme there are PNGs embedded in the SVG, which makes the difference. The Qt-bug obviously only applies to pure SVGs. So I just had to exchange the panel-background.svg in /usr/lib/kde4/share/kde4/apps/desktoptheme/widgets with a similar looking one that has the gradients embedded as *.png.
I must confess that it does not look 100 % exactly as it used to look without desktopeffekts (as there are a lot of transparencies..) but it's definitely better than the old one (with desktop-effects).
I'll try to get it better, when I've got the time - but maybe (for sure) the Oxygen-Artists will do even better then.
As on a forum someone pointed out, that with the Heron-Theme, this panel-bug does not occur, I investigated into it and just found some quite simple workaround for that bug:
in the Heron Theme there are PNGs embedded in the SVG, which makes the difference. The Qt-bug obviously only applies to pure SVGs. So I just had to exchange the panel-backgroun d.svg in /usr/lib/ kde4/share/ kde4/apps/ desktoptheme/ widgets with a similar looking one that has the gradients embedded as *.png.
I must confess that it does not look 100 % exactly as it used to look without desktopeffekts (as there are a lot of transparencies..) but it's definitely better than the old one (with desktop-effects).
I'll try to get it better, when I've got the time - but maybe (for sure) the Oxygen-Artists will do even better then.