While this bug has existed since the initial release of the FMSLogo screensaver, it only became noticable now, as I recently implemented the windowing command set in the screensaver, which makes it possible to show/hide windows on top of the screensaver. When a window is hidden, the WM_ERASEBACKGROUND message is sent to repaint the region where the window was. Due to the bug, the entire screen would be made white, then only the region under the window would be repainted with WM_PAINT.
