I’ve been trying for a while to get the Mac “Screen Sharing” to work. I want to control the Mac from a Windows Vista machine. Even though Screen Sharing is just a VNC server, my RealVNC client would seem to connect for a split second and then the connection would go away.
I finally found the solution: in the VNC client (vncviewer) options, set the encoding to “Hextile” and the color level to “Full”. Now it connects fine!