When riding and fighting on a "Barded" swamp dragon. When the barding wears off of the dragon you are unable to dismount for a time. Eventually you are able to dismount. usually about 20 to 30 minutes later.
Update: Killing yourself will obviously dismount you. Also PVP dismount will dismount you, however double clicking yourself will not. get the message *dismount blocked*
Comments
Weird bug
If you are in EC and have actions blocked on self, that is your problem.