I have Vine Server running as a system-level server on :0 (port 5900). Using fast user switching I’ve logged in as myself and started Vine Server on :1 (port 5901). If I remotely connect to :1 it works fine for a while, but after an unpredictable amount of connects and disconnects I am prompted for a password but I briefly see a window that’s smaller than it should be then I get a disconnect. For a VNC client I’m using VNCViewer version 4.1.2. It is possible to also get my system-level :0 Vine Server in the same way.
As a workaround I connect to :0 then stop/restart Vine Server on :1 and :1 starts responding normally.
Anyone have an idea of what is the problem?
We’ve honestly never seen this issue reported. It may be an interaction issue when using that specific client.
What version of the server and what version of Mac OS X are you runing?
Server: Vine Server 2.0 (though this happened with OSXvnc as well)
OSX: 10.4.8 (though this happened with earlier versions as well)
Client: RealVNC’s vncviewer 4.1.2.0 VNC Viewer Free Edition for Win32
Is there some way I could enable logging that would help you to understand this issue further? It is a very annoying problem, so I’m very motivated to help! 
The problem I described above was happening again – I made a connection to Vine Server and it immediately disconnected. I selected “Shared connection (do not not disconnect other viewers)” under the “Misc” tab then I tried connecting again. The connection happened as expected.