If you try to create a team "x", everything looks fine as you create it, but as you walk away from the counter the name becomes "Ex". DanWaD also tried it and the same thing happened.
This also seems to happen with some parties.
A few days ago I saw an E on like 30% of the games, but currently not so much.
Was thinking of a humorous trend I didn't catch, but apparently it really is some kind of bug. *shrug
It's Happening when mew tries writing her guild cards too! Will find "J J JHarborer of Hope! *Pounces the EVega-san!* =3" J's and E's appearing Every time when returning back to writing cards. =/