Shiff is correct in that this can happen when crossing servers while mounted. The annoying thing is that the module will, while it's running, remember your character's state despite most attempts to convince it otherwise. For example, if you "ride" from West to Central, dismount through some means and come back to West leading your horse, West will still think you're mounted.
So yes, it is advised that one dismount before crossing servers.
Now then, the good news is that West will forget all about this once it's restarted.
The bad news is Kurgin's faithful Th'hawaururk ended up on the dinner menu at the Ogre Cafe'.