Yes, I am familiar with that torn screen image (somewhere along the way the correct resolution of the screen is lost).
I can reproduce it reliably (in fact, I cannot get around it for the use I am trying to make).
I am running a current model Mac Mini with OS 10.5.5 and Vine Server (same problem with both 3.0 and 3.1b2). This mini is headless – no display, keyboard, or mouse – just connecting through LAN with VNC. I am trying to get it to boot up and setup several logged in users (using Vine Server and fast-user-switching) so I can have multiple users connected simultaneously.
When I first boot up, the display is fine via vnc and I can log in. However, whenever I fast-user-switch, the “System Server” instance of Vine Server goes to that unreadable torn image and no amount of fiddling, logging in/out, or fast-user-switching will repair it. Only a reboot will set it straight again.
If the first user to log in runs their own local Vine Server, that screen is fine, too, and it stays good after I do a fast-user-switch (which makes the System Server screen go bad). However, if the second user (the one being logged in by fast-user-switch) also runs their own Vine Server instance, that screen is bad, too. So, I can get more than one user logged in, but never more than one is accessible with a viewable screen via vnc.
Now, if I plug in a physical display (vanilla VGA monitor with the Apple-supplied DVI to VGA converter) everything works perfect. So, that led me to try shorting out the monitor ID pins on the VGA connector, instead of plugging in the actual display, like we used to do with old macs to trick them into booting up headless. But that didn’t help any.
Anyone have any ideas for how to get this headless, multi-user server going?