The issue isn't with your SEF or anything like that, it's with the large GoDaddy header at the top. We're making AJAX calls to your site to see if a name is available, and that returns a 'page' with true of false. However, GoDaddy seems to be inserting their banner at the top so our true or false is coming back with a bunch of gobbeldy-gook. You can see from the page below:
<!-- m --><a class="postlink" href="
www.industrythoughts.com/?option=com_jfb...le&username=testname">
www.industrythoughts.com/?option ... e=testname
There's a '1' at the bottom indicating that 'testname' is available, but the login pages' javascript is reading the header code. It should just return a blank page with a '1' or a '0'.
Is there any way you can turn off the GoDaddy header? I think you'll have many AJAX related issues if you can't. The other option is to remove the two 'onblur=' statements from the username and email fields in the following file. This will prevent the AJAX calls:
componentscom_jfbconnectcomponentviewsloginregistertmpldefault.php
Good luck