[Juser] Newbie: Creating account issue: Adium X Mac OS X

[Cocoa Ninja]

Hi,

I'm new here. I could registered myusername at jabber.org server, by  
using the latest version of Adium on Mac OS X. After making an  
account suceessfuly, I couldn't connect to the server using the name  
after logging-out.

I saw an error message saying:
Invalid Jabber ID or Password
Jabber was unable to connect due to an invalid Jabber ID or  
password.  This may be because you do not yet have an account on this  
Jabber server.  Would you like to register now?

so, I hit "Register" and then saw the error message "Registration  
Failed, 409:Conflict".

It seems that the username I registered still exists, but cann't  
connect. What could be a possible cause for this?

Any help would be greatly appreciated.