Whenever I dismount, usually (but not always) there is a delay (sometimes up to several seconds) in when my head reappears. When I don't have a head, I cannot interact with farming nodes in the world and cannot open doors.
It is especially bad in Cyrodiil when there are lots of other players around me. I couldn't enter a keep door for a good 5 seconds sometimes and another time I was even killed because of it.