Desktop effects disabled after connection 2nd monotor

[regenerate]

Hi All,

I've installed Ubuntu 9.04 on my Acer Aspire 5633WMLI laptop and Visual Effects (set to 'Extra') and compiz effects (like the desktop cube and rotation) all worked great. After connecting a external monitor however, the Visual Effects is now set to 'None', compiz effects don't work anymore and I cannot enable these anymore. When I try enabling the Visual effects I get a pop-up with the notion "Desktop effects could not be enabled". Disconnecting the monitor and restarting the laptop doesn't make a difference: all effects are disabled and stay that way. Working without the effects makes gnome much less user friendly, scrolling through (web)pages is now quite a shocky experience, not great to work with.

When the external monitor is connected, xorg.conf looks like this:

[CODE]Section "Monitor"
 Identifier "Configured Monitor"
EndSection

Section "Screen"
 Identifier "Default Screen"
 Monitor "Configured Monitor"
 Device "Configured Video Device"
 SubSection "Display"
  Virtual 2560 1024
 EndSubSection
EndSection

Section "Device"
 Identifier "Configured Video Device"
EndSection
[/CODE]

Since the effects do work fine with one monitor, I don't think this is a hardware limitation, but correct me if I'm wrong :).

So my question is: how to re-enable the desktop effects, preferably also when the external monitor is connected. If you need me to provide more information, please ask.

[StonedGiant (jaswasniewski)]

I have the EXACT same problem as described on my HP Compaq nx7400 laptop

[Travis Watkins (amaranth)]

This actually is a hardware limitation. When your Virtual size is larger than 2048 in any direction DRI is disabled so of course compiz and any other 3D apps are either not going to work or run slowly. Based on your issues with scrolling it sounds like it also disables all other acceleration as well.

Basically, you cannot have desktop effects (or desktop acceleration of any kind, apparently) and use a second monitor or even an xorg.conf that would allow you to plug in the second monitor at any point.

[StonedGiant (jaswasniewski)]

I did a fresh install and everything works fine so surely this can't be the case

[Travis Watkins (amaranth)]

Again, a hardware limitation (or, really, a driver one but not worth tracking in Ubuntu).