Two servers, both NW 6.5 SP3. Older server permits AFP connections, newer
one doesn't - immediate "Login failed - Sorry, the password you entered is
incorrect. Please renter it" error. Same userid/password works
connecting to first server. Same AFPTCP module loaded on both servers.
Errors on loading AFPSTRT.NCF:

at console:

Desktop on volume _ADMIN is unavailable to AFP clients.

from afptcp.log:

Tue Jan 17 12:26:15 2006
: Thread ID = 247, InitAuthentication: RegOpenKeyEx 'Appliance' failed
1073741838 <4000000e>
Tue Jan 17 12:26:15 2006
: Thread ID = 247, Using Mac Code Page <Roman>

One potential item of note: Universal Passwords were implemented in the
tree between implementation of the first (working) and second (nonworking)