When you create your account, be sure that you're connected to guildenstern.dyndns.org.
Also be sure to use a JID of (in your case) arkadiy@guildenstern.dyndns.org.
Feel free to mail me at peter@mirrorshades.org, peter@guildenstern.dyndns.org, peter.whysall@ntlworld.com or pwhysall@technology.serco.com, if you still get no hot Jabber lovin'.