Sharebuilder is a pain, but you may run into other problems by removing money from a tax-deferred account. You can do it the way you suggest, but you have to be sure everything goes smoothly.  One thing that will happen  is you  will not receive all the money in your account because taxes will be withheld. You will have to cover the amount held and add it to your new Roth. That should only be on earned income though, but if you don't restore it you will be hit with a penalty.

Paul