How can we prevent Putty from dropping SSH-connections?

Research revealed that newer versions of Putty running a default configuration will request to re-send the authentication information after a certain period. Putty will drop the connection if it does not receive this information.

To prevent this from happening you can set the Chokes on PuTTY's 'winadj' request setting to "On". Please see the picture below for PuTTY version V0.64.