Had so much trouble with this to get it working that I thought I would post it here. I have it working ok now on about 10 sites.
3725 with 1 e1/t1 & 30 Digital Modem card.
Allows users to dial in Xauth with RSA ACE server then calls them back and then you can bring up the VPN. Works great...
Let me know if this helps or any suggestions welcome.