The latest version of the OpenVPN client allows for the elimination of the login user name and password from the computers memory. This is beneficial in high security applications where always having to enter the user name and password when reconnecting is desirable. The default configuration for SurfBouncer is to have this feature turned off, as it results in frequent prompting for the user name and password and is not necessary for most people.
In order to turn this feature on, in your setup place the following:
auth-nocache
in your surfbouncer.ovpn configuration file. This will force a password request every time the connection re-negotiates.