Check the properties of your UI_ToonName_##.ini file.. Make sure it's not read only..
For ex.. Mine is UI_Hawkren_91.ini..
I would open my everquest folder look for that file and right click it.. Then click properties.. Where it says attributes: make sure read-only is not checked..
That's all I can think of to cause this..
EDIT: Never know though could be a new bug