I've just setup remote access to a Windows XP box using RealVNC. When the user runs an app, they expierence issues with "screen painting" - the screen doesn't paint well, except for a radius around the mouse cursor.

The app is displaying a calendar. I am not sure what it is written in (think it is a .NET app)

Have no problems getting/staying connected. Initially it seemed to be working fine. I have looked through all of the settings as far as compression and speed.

I can replicate the issue from more than 1 location. The hosting Internet connection is DSL.


In my opinion RDP works better than VNC. However if you must use VNC, and there are plenty of situations where RDP doesn't work, then I've had much better luck with TightVNC and using the Mirage Mirror Driver.

  • Thanks for the tip on the Mirage Mirror Driver - will try that tonite! – Cybersylum Mar 19 '10 at 18:28

I've seen this, or something like this, very frequently with different VNCs. The most common occurrence is to have VNC not repaint background screens. A classic example is using the start-menu to access something that causes a window to pop-up, but VNC never gets around to re-rendering the background to eliminate the now un-popped start-menu. Forcing a screen refresh gets rid of it. I've seen this most commonly when accessing UltraVNC servers via TightVNC on Linux, as well as accessing RealVNC servers via UltraVNC on WinXP.

What is uniformly buggy with VNC is accessing Java applications, which don't seem to fire the correct 'screen is refreshed' events for VNC to pick up that it has to repaint the screen. I've had both RealVNC and UltraVNC do that.

Because of all of this I prefer to use RDP wherever possible, since that performance is decidedly better. Even on Linux talking to Windows. However, network policies on the work network discourage RDP so I don't get to use it much.

  • Thanks! I'm in the same boat - policies are against RDP here. – Cybersylum Mar 19 '10 at 18:31

The problem is the mirror driver. I'm using RealVNC for Windows V 4.6 (although this fix works for older versions too). I have not tested it with RealVNC running on a linux server, connecting with a Windows client.

Just turn off the mirror driver. The refresh will be slower, but Java apps (for example, the Cisco ASDM GUI firewall config tool) will no longer need to be manually refreshed.


It sounds like a network issue to me. Check the connection between the VNC client and server for latency and packet loss.

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