How can I disable "ask to share" in Lion Screen Sharing?

Hello,

This change in behavior is making Screen Sharing via Back To My Mac useless. I have 2 iMacs that are in shops, and each iMac has an Admin account and a non-admin account. So, as long as the non-admin account is logged in (which it is most of the time), when I want to control the screen I have to "ask permission" of that user OR use a "Virtual Display" which is painfully slow.

I understand the value of the ask for permission, but why can't I opt out so no matter what I can just control the screen? HELP!