Not fixed on my BT YouView DTR-T1000. Menus etc disappear the second the HDMI is plugged in. Second hand machine, so I don't know if active BT customers get a different set of software updates from non-customers like us, but we get all the Humax updates.
Darned annoying, though since we largely use SCART to archive progs to a DVD recorder, at least they don't get spoiled by announcements that the box is beginning to record a scheduled programme. If we want one day to feed another room, it would be awful.