Can not Register new user with Ajax Register

When users try to register they get the following:

The name you entered is not valid.
The username you entered is not available. Please pick another username.
The passwords you entered do not match. Please enter your desired password in the password field and confirm your entry by entering it in the confirm password field.

Thanks for the help.
~d

And now when turning off the ajax component i get a 404 error with the standard joomla registration. Please help.

I did get my original Joomla registration working. I found the other plugins besides the component to disable. But still would like to get the Ajax Register working.
Thanks

The problem was another captcha was stopping the registration. I removed that and now user can register.
Sorry for the post.
~d