SQL Server 2008 R2 External Database Support

I'm trying to configure WDM 4.9.1 to connect up to my standalone SQL 2008 R2 server.

No matter what I do, the installer fails saying it cannot connect to the database. The SQL Server shows the connection and says "Login failed for user 'rapport'. Reason: Password did not match that for the login provided." I've tried numerous passwords, default passwords, creating simple passwords (aka, disabling the complex requirement). I installed tools on the WDM server and can confirm I can connect to the SQL server with the correct username/password and modify the database. I tried using the SA account and that failed. I installed SQL 2008 R2 Connectivity and Management tools of both 32 and 64 bit on my WDM server.

I've stopped short of a packet capture to actually look at the data going back and forth... but I'm hoping someone might have an idea?