This article provides brief information and steps to resolve the issue when Mac OS X 10.8 requires VNC users to authenticate using the logged-on user credentials. This results in a preemptive MRC sessions when using the MRC VNC viewer, logging the local user out of the system.
DameWare Mini Remote Control version 9.0
To emulate the default VNC server behavior from prior to OS X 10.8, install a third-party VNC server, such as RealVNC. This allows MRC to establish non-preemptive sessions with OS X 10.8 clients and connect using MRC user credentials.