I have a minor problem with my much-loved Pentax LX that Pentax UK and a very highly regarded UK repair company have been unable to fix. The camera works fine but every so often the metering "sticks" on over or LTB and it takes a wasted exposure or so to clear it. It has been suggested, and I tend to agree, that maybe it is a microswitch problem on the mirror box? The main circuit board and other parts have all been replaced but the problem never seems to go away. Has anyone come across this before or know a fix - other than carrying a separate light meter, etc?