ODBC + MS-Access fails with MD5 pwds if not specified in DSN

I have pgsql 7.2.1 and pgsqlODBC 7.2.1.

The connection fails under these conditions:

Server set up to accept md5 passwords
ODBC DSN is created without specifying the password at that time

When attempting to use the connection in Access, the pgsql ODBC connection
dialog is displayed asking for login/pwd; enter it, and you receive:

[ODBC] - connection to '<database>' failed.

The log files seem to indicate that Access is trying to authenticate with
the Access login and password (by default, login="Admin" and pwd is blank)
instead of the login/password I supply in the pgsql dialog:

=====
CC_connect: entering...
CC_connect(): DSN = 'someuser', server = 'myserver.mydomain.org', port =
'5432', database = 'someuser', username = 'Admin', password=''
connecting to the server socket...
connection to the server socket succeeded.
sizeof startup packet = 292
sent the authentication block.
sent the authentication block successfully.
gonna do authentication
read 9, global_socket_buffersize=4096
auth got 'R'
areq = 5
in AUTH_REQ_MD5
CONN ERROR: func=PGAPI_DriverConnect, desc='Need password but
Driver_NoPrompt', errnum=112, errmsg='A password is required for this
connection.'
=====

However, the connection works fine under *either* of the following conditions:

I provide the login/password when creating the ODBC DSN
I change MD5 to "password" at the server.

Any suggestions for getting md5 passwords to work with an interactive Access
ODBC login? We cannot put the passwords in the DSN, nor can we allow
unencrypted passwords over the network.

Thanks