Last modified: 2010-05-15 15:29:26 UTC
Currently when you try to block a non-existant user in Special:Blockip MediaWiki will display the 'nosuchuser' message from Language.php. Currently that message also reads "or use the form below to create a new user account" which doesn't make sense on that page. I see three options: 1. Adjust the 'badipaddress' message and use that one instead. 2. Adjust the 'nosuchuser' message. 3. Make new message.
Fixed in cvs. Thanks for the report.