I'd consider this more curiosity, but it may be a bug. What is the logic behind the order of the character select screen? It seems regardless of what 'Create a New Character' button you select that it re-orders them as it sees fit. I made a mule character and he moved above my main in the list, so I have to make an extra click every time I want to login. Minor annoyance, so not a big deal.
It lists your characters in alphabetical order, so I would assume you named your mule something that was alphabetically higher than your main's name
