Have a look at the bug in gnome:
http://bugzilla.gnome.org/show_bug.cgi?id=354767#c5
It was closed, apparently the Composite X extension in nVidia is buggy.
That would probably explain why the bug went away when the new driver
was installed.
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gnome-terminal does not start when using xinerama
Public bug reported:
When Xinerama is enabled when using the proprietary nvidia drivers,
gnome-terminal fails to start. When run from an alternative terminal
(konsole), the error is:
The program 'gnome-terminal' received an X Window System error.
This probably reflects a bug in the program.
The
Sorry, it's not different. I thought it might get filed against xorg or
something other than gnome-terminal.
This is my first bug report, so sorry about the noise :)
Feel free to close this.
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Gnome-terminal fails to start when Xinerama enabled with nvidia-glx
https://launchpad.net/bugs/64623