No name Characters

i'm back after some time of not playing, and i notice some of the characters i had disapeared in some of the realms i had them. when i check the realms list i see a number of characters listed in each realm i used to play in, but some disapeared and others have no name, which prevents from login in with those characters.
i have in icecrown 10 characters, of which 1 has no name. lordaeron had some, but despite being listed in the realms list taking space, after i enter they dont apear either, in the case of the pvp realm blackrock, all of the characters have no name.
in all honesty if nothing can be done with the blackrock and lordaeron characters, im ok with it. but at least the DK in icecrown id like it to be available again.
Last time i remember that character had the name Deroald, and its a Human DK, lvl 80.
thanks in advance

Try logging in again and you will be asked to change the name.