UltraVNC server under XP shows a black screen in the viewer

[UltraSam]

This one is now a classical

One of the related thread is here:
topic #307


To sum up:


*** mösti explanation and workaround ***

When you connect to a remote windows using vnc you connect to te real screen. If you than also make a connection using RDP the real screen is blanked as you see in vnc and an windows uses an other driver for sending the screen trough rdp.
If you reconnect vnc you also connect to the "new" driver windows had loaded and you see the same screen as on your rdp session.
Then you disconnect your rdp session windows returns to the driver of the real screen and your vnc session shows a black screen because the rdp session driver where it is still connected to really gives a black screen because it isn't used anymore.

You have the same with switch user, only the user who logins first in windows has control over the real screen. The others are virtual.

But reconnecting vnc always works and solves the driver switch because it then reconnects to the display driver too.

***


*** Andrei workaround ***

You can still run both Remote Desktop and Ultra VNC at the same time.

Just connect to your computer from 2 different IP addresses: with Remote Desktop from one IP and with VNC from a different IP. (In most cases, this entails that you should do this from 2 different computers)

***

Thanks for their contribution

[bevtech]

Additions on to this problem

When Running UVNC in service mode Fast User Switching is not supported.

The workaround would be to run UVNC in application mode and drop a shortcut into the every users startup folder.
<b> Keep in mind that only one user can be logged in at a time</b>

Developers Summery

The problem is that MS made some changes starting with the release of XP.

A service can only be inteactive with session0.
Prior to XP, Session0 was always the desktop...after XP, and for
some unknown reason, onces you used "FUS"(Fast User Switching) or RDP (Remote Desktop Protocal) the console session become 1 or 2...

Running as service, the OS block access to non session0
Causing -->black screen.
MS made sure you only can use RDP to make a connection,
first with FUS, win2003 after RDP, Longhorn is a total block.

This is not only a vnc problem, but all remote controle application have the same problem....only RDP is not affected by this.

For Example:
Even Pcanywhere was having the same problem for more then
a year, but know it seems finaly fixed.



Vnc running as application ->all OK
Vnc running as service -> OK until you switch user or use RDP.

For fast user switching, we try to activate a seccond vnc session running on the next available port, 5901
I don't know if the same trick works after RDP made a connection.

This will take alot of research and development to fix so please be patient.


Other Tips:

Any 3D pointing mouse can cause this issue along with not using classical windows desktop themes.

Try using the default pointer and the default windows theme to see if this elimates the issue.

[redge]

uvnc 104 solved the problem.