Authentication problem with a Cisco 3005 concentrator

Archived from groups: comp.dcom.vpn,comp.dcom.sys.cisco (More info?)

I'm trying to add PPTP connections to an existing Cisco 3005 setup.

For authentication, the concentrator has two servers setup, Kerberos/AD
(I think that's what the setting says...I'm going from memory) and
Internal. I think I've got the PPTP part mostly working, but I'm
getting errors that look like:

64411 04/27/2005 16:59:25.720 SEV=3 AUTH/5 RPT=423 192.168.1.42
Authentication rejected: Reason = Invalid password
handle = 91, server = (none), user = myusername, domain = <not
specified>

And I'm sure the password I'm using is set correctly both on the
internal username and also the external server.

What should I check for? Why does the error say "server=(none)"?

Thanks!