Anybody able to help with Windows Remote Desktop black screen issue?

[Dowlphin 463]

OK, since I'm not registered in any IT forums and wouldn't even know which one to choose, I'm trying here.

My problem is that if I connect from my main WinXP_SP3 machine to my secondary WinXP_SP3 machine using Remote Desktop while the secondary has just loaded up and NOT logged in with a user yet, the client will eventually begin to show the first few segments of the desktop wallpaper and then stop. Nothing will happen and I have to close the client. When I check what happened on the target machine, I see RD's lock screen. When I try to locally log in (before or after having closed the RD client, no difference), the screen turns black. The harddisk doesn't work, so apparently it doesn't log in properly. Trying to reconnect with RD at this point will fail. It's trying without success, for all eternity.

Now I found reports of exactly this on the WWW, often in connection to an nVidia graphics driver, but the target system has an ATI one.
One recommended to add a variable in the target machine's registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
SessionImageSize=0x00000020

While it seemed to have helped some people, I tried it (and later also tried somewhat increasing the value) and it didn't fix the problem. When I uninstalled the graphics driver completely (including the hardware manager entries, total bare mode), RD still has the same problem, with the only difference that when I try to log in on the target machine after that, there's no black screen, just a freeze.

Then I figured out what caused the problem, but it doesn't make any sense to me: When I, in the RD session options, activate the show-desktop-wallpaper option (and only that, it's totally independent from any other settings there), the problem occurs. If I deactivate the transmitting of the desktop wallpaper, I can log in just fine right after the target machine loaded Windows.

Both systems are using the same resolution and refresh rate by the way. They are quite similarly configured.

I have an awesome Fluttershy wallpaper on that machine and I wanna see it when I log in remotely!

I then used a simple blank white test wallpaper of the same size and display mode. That worked! How crazy is that? It's a BMP, an uncompressed format, and uncompressed anyway once it's in the RAM. The same amount of data. But I did tests with several wallpapers and the chance for a lockup actually increases ... get this ... with the complexity of the wallpaper image. I used some scribbles on a plain colored background - fine. Small cutout of Fluttershy's face added - fine. Bigger cutout added that roughly filled 50% of the wallpaper - freeze.

 

Another thing I tried is log in on target machine, then log back out, then log in with RD. Result: success.

Any idea?

Edited June 10, 2013 by Dowlphin