Website Switch Url Issues

I have a website running on a whm / cpanel server. When you create the account it gives you a link of ip/~username to work with until the dns resolves. I have deployed 40 sites on my server by first using the give ip/username combo then when the site is ready moving the dns over and changing the wordpress url and site address under general in setting, But i have run into one of my sites when I change the settings and click save it bring me to a blank page and my site stops working. I can go into the database and change it back to the ip/username combo and it works just fine. I was wondering if anyone else has had this issue.

* when i say stop working the front page will load but none of the links will work .