I had a little conversation with the site admin via e-mail.
First of all, he assured me that the artwork is not for sale. To be sure about this I registered at 1zoom.ru under a different nickname, and all I can do now, is to confirm the guy's words - all the pictures are free to download for every registered user, and the registration is free as well.

Then he told me that it would be a plenty of work to ask permission for every picture he gets. And he doesn't know what to do in this situation. It's up to you now. I personally think, there could be a way out of this if you allow him to ask permission only once, for all your former and future artworks. Sounds wild maybe, but I think, there are no other options.

Now about the signature problem. That is something I should talk to Aleni about, because she (it's a girl) cuts off the signature before sending the picture. The admin gave me her ICQ -number, so I can solve the whole problem with her personally.

I will setup the ICQ in a couple of hours, and then I'll try to reach her.