Just downloaded 113.02 Firefox. Frame around firefox windows and tabs loses Min/Max, "X" exit button and full screen buttons. Coloration of the frame also changes from solid to opaque and back without any input from me. Does seem to vary based on memory usage. High usage appears to cause these symptoms but can't be sure. Controls do not reappear. Double-clicking the frame makes them reappear only momentarily. Uses Windows 7 Pro OS.