How to use Mac OS X "Per-user screen sharing" from a Windows PC? I am trying to use the "Per-user screen sharing" feature in Mac OS X Lion.  This is different from regular screen sharing in that it allows you to log in to your account on the Mac remotely without disturbing a different user who is already logged on.  What what I can tell from experimentation, to use per-user screen sharing you must disable the 'VNC viewers may control screen with password' option.

I am trying to connect from a PC. Problem is, I can't get it to work.  TightVNC complains, Server did not offer supported security type.  UltraVNC says No supported authentication methods! and RealVNC has the nerve to tell me to turn on the "control screenwith password option" which would disable the very feature I need, per-user screen sharing!!!  (To connect to Apple Remote Desktop (10.4) or Screen Sharing/Remote Management (10.5 onwards) built-in to Mac OS X, turn on the 'VNC viewers may control screen with password' option.)

I have trouble believing that it is impossible to connect to per-user sharing just because I am not connecting from a Mac.  At the moment the only work-around is to connect to a different Mac using single screen sharing and then VNC to the other Mac.  Quite frankly, that is ridiculous.
The trick to doing this appears to be the following: under Computer Settings you need to enable VNC viewers may control screen with password but NOT enable Anyone may request permission to control screen.  You then enter a control password which grants access to the login screen, and use your own local username and password to log in.