Thanks of course you are right, I have mistyped the IP-Adress. However
I get the login page displayed correctly (1.0.beta12) and I am using these credentials but I always get invalid login. (and no, caps lock is not enabled)
Connect a monitor on the pc running ZS. After the boot has been completed you can see the initial screen displaying the username and the password. If it is not shown, it means that someone has changed it. Check if there is an active profile, erase it and create a new one.