Do a search on cisco's site for DDR, maybe throw in ISDN.... there is a good amount of info about setting up DDR http://www.cisco.com/warp/public/471/top_issues/access/793_config_bri.html
This might sound stupid, but it is usually the first thing that I ask a user with a proble.....Did you restart the device?If the answer is yes.. I would use the erase nvram command in the privledged mode and start with a fresh config....that way you ...
I am currently Doing the exact same thing..... but waiting for hardware. Using a 1720.....waiting for the WIC-1B-U card. I have been reading from cisco's site (search DDR vpn ISDN)and have found some good info about setting up the DDR.... (dial on ...