Arrrrrgh. There's two thing I hate when registering with a new website or service.
First one is when they ask for logins longer than 3 letters. When I'd like to keep things simple and use the same 'Ozh' as a login across a thousand websites, I end up registering (and forgetting) gazillions of ozhy, ozhozh, ozh1, ozhozhozh, MrOzh and such variations.
But what infuriates me even more is when I try a new service, 3 letters are ok with them… and some jackass has already signed-up using my name. Because, well, yes, it's MY name, you see. Die, jackass.
You seemed to be in mood for some alias/domain locking lately. Hurry up, ozh.vox.com is still available, if you are interested ;)
You should use a longer name that is probably not taken like userozh or even uozh. Luck I haven't had your problem yet.
@Yann
Vox in invite only last time I checked. If you got an invite please let me know via my site's contact form:)