git authentication problems

I have the TeamCity service running as local system account.

In my VCS configuration, when I set the authentication method to Default Private Key, I get the following error:

Test connection failed in AtlanticBT Common Code :: AtlanticBT.Common.Types 4.0 :: Master. List remote refs failed: com.jcraft.jsch.JSchException: Auth cancel


The Default Private Key is mapped to:

C:\.ssh\config


However, when I set the authentication method to Custom Private key, I set the Private Key Path to the same file:

C:\.ssh\config


And I get a successful connection.

How can I set it to use Default Private Key?  The key works obviously since I'm using the same path for both Custom and Default Private Key.