Nickname already taken/invalid.

I try to change my nickname but origin says its already used. After checking origin users, account name seems not to be used. I'm using the same nickname for all Battlefield series: BF: P4F, BF:H, BF:BC2 and i wish i could use it in Battlefield 3.   For now my nick is xXxDMSxXx but i want to change it to DMS667 like in every other Battlefield game.