Server 2008 demand dial VPN

I have 12 buildings that I am building demand dial vpn's through Routing and
Remote Access. I have created the AD account for dial, and configured the
demand dial on both ends. I can't get them to connect for a generic error of
username/pw.
Also, using l2tp with a shared key.

But if I create a dialup networking vpn, I can connect fine.

My need is to have a persistent connection for client traffic from each site
to be routed over..

any ideas of something I am overlooking??