Probably far too late a reply to be relevant but I don't check in that often (a bit more now that I am feeling the start of a hankering for an F800GS (it would be my third)).
I currently own a K1300R. The K1300 series occasionally suffer from stalling, usually when accelerating from standstill, say when moving off from traffic lights. While no complete resolution has been found (to my knowledge), I strongly suspect that it has to do with a less than fully charged battery. Could it be that the 800 twins also require a well charged battery to avoid unexpected stalling?