Comment 5 for bug 945608

it looks like we are not rendering background for labels that are not currently selected in a way that cairo/pango expects. Filling the image with Qt::transparent is not enough apparently.

I've added gtk_render_background and related styling code locally in IndicatorEntryWidget::updatePix() and to CroppedLabel::paintEvent as a stopgap and found that it fixes the issue - http://ubuntuone.com/3Du1qgddWLHeHUdxXHY2ND and this has nothing to do with the Radiance theme itself.

I know unity-2d is no longer developed but in case somebody is looking for the reason - that may be it.

I hope that's also the reason of bug 723167 in Unity/Compiz too.