Chromium gets decorated ramdomly

This falls in the department of silliness that are very annoying:

Every once in a while, Chromium has its window decorated by the window manager. It occurs several times a day since I upgraded to OpenSUSE 12.2 x64 with KDE. All the latest patches are applied and am running from the official repositories.

Normally and with every version from 12.1 and earlier, Chromium appears without window decorations and draws its own frame with handles its own events (which I happen to have written some of that code). Now, since I upgraded to 12.2, the window manager occasionally draws its usual frame (the same as for other applications) around the frame drawn by Chromium.

This is annoying because when that happens, the Chromium window shifts down to accommodate the extra title-bar and that cause it to be often hidden below other windows. I normally work with Chromium full-height and other applications slightly lower to make switching back and forth quick.

Any idea what is going on and how to stop it? It is most likely a KDE issue which I am not entirely familiar with since I started using it when I finally upgraded to 12.1.

Thanks in advance,