as cb521 said, Fidelity works. i transfer usually every few months, but recently decided to stop buying through ast and contributing to the dilution. TD first told me over the phone that they would transfer znog, then i set up an account and they denied the transfer.
if i remember correctly, and this was about 2 years ago, after the denial, they told me that if i had a certain HIGHER number of shares/$ value, they would transfer. i want to say in was at or near 6 figure value minimum.