Desktop effects stopped working on Ubuntu 9.04

[Oron Peled]

On Tuesday, 13 בOctober 2009 20:29:07 Ori Idan wrote:
> Thank you very much.
> I had to delete the display section and restart X

Generally speaking, the Xorg developers recommend working without
an /etc/X11/xorg.conf at all (assuming your distribution package
a recent Xorg version + drivers).


> On Tue, Oct 13, 2009 at 7:37 PM, Ori Berger <linux-il at orib.net> wrote:
> 
> > Ori Idan wrote:
> >
> >> I have an Ubuntu 9.04 laptop with Intel 945 graphics adapter.
> >> Desktop effects worked until this morning when I connected it to an
> >> external monitor.
> >> After disconnecting the external monitor and restarting the laptop,
> >> desktop effects stopped working.
> >> Does someone have an idea how to reenable them?
> >>
> > It's a known bug in the Intel driver: You placed the external screen to 
the
> > left/right of the laptop screen, causing the effective screen width to be
> > one that the Intel Driver does not support 3D acceleration for, thereby
> > causing compiz to turn off effects.
> >
> > If effects won't turn on, check /etc/X11.conf under section "Screen"
> > subsection "Display" to see it doesn't still list a too-wide screen (your
> > laptop is probably 1024 or 1280 pixels wide). When this happened to me, I
> > deleted the "Display" altogether and let Ubuntu re-figure it out itself, 
but
> > a "sudo dpkg-reconfigure xserver-xorg" might be helpful.
> >
> > And from now on, when you connect an external monitor, just be sure to
> > place the screen above/below the laptop screen rather than to the 
left/right
> > of it.
> >
> 

-- 
Oron Peled                                 Voice: +972-4-8228492
oron at actcom.co.il                  http://users.actcom.co.il/~oron
The Micro$oft principle: Make bugs, not war