Why won't my Yahoo Display Name change?

Every time i try to change it in the "edit my personal info" it comes up that the name is invalid. i want it to be "Kikikat" why wont it let me put that?

I keep trying to change it from my real name to something else like "Kikikat" or "kiki" or something cute like that. but everytime i try it says "invalid" nothing seems 2 work =/ help?

How come when I change the display name on my Yahoo email account, the From: field on email messages that I send still shows the old name?

I went to "Edit My Preferences" and tried to change my name and it keeps on saying "Unable to save at this time. Please try again later."...I've been trying to change it every day since last week LOL... whats goin on?? HELP !! thanks...

I went to my activity hit edit preferences and then change name i changed it then i hit submit and it never changed it just stayed the same.

So im actually trying 2 find this answer 4 my dad. He wants 2 know how your able 2 change your display name on yahoo messenger, Like righ now his current display name is Robb on yahoo messenger, but he wants it to say Robb Porter on his yahoo messenger...

I set my yahoo messenger, but I cannot figure out how to change my display name for people. I know how when I first request and to go on my messenger list, but this also the display name this person will always see. Or will they see the display name...

I know this has been asked a million times, but I can't find the answer I need through Google or Yahoo. I've changed the picture and name on my Yahoo! profile successfully. But as far as being able to change the avatar and display name on the Answers...

everytime i join a room with different people and put an instant message in the window it says (my email address): __________ and i don't want it to say my email address and show it to all these people i don't know!! how can i change my display name...