Comment 16 for bug 437378

The claimed assumption that kwin would set size and position independently if there's a combined configure request is (afaics) wrong, the geometry update is blocked in the configure request until everything's done (position/size/contrainment)

There /might/ rather be a relation to the "dirty texture" issue, however as Martin pointed we've had former reports on "cairodock + qt + opengl = weird issues", therefore

@Cédric
you should figure whether it does also happen with the xrender backend.