[Pharo-project] Slow Image removes window decoration

An hour later, the pharo application goes full-screen on the second monitor, losing the window border, including title bar and icons. The updating continues, and an hour later finishes. I've tried interrupting the update process, but those interrupts only arrive after the update finishes. After saving and restarting, I now have a Pharo image without a window border. Reproducing the issue might be, uhhm, slow. Stephan