Section "ServerFlags"
# disabled xinerama, because I want two separate screens
Option "Xinerama" "on"
EndSection
This statement in your xorg.conf doesn't make sense.
Xinerama is the key to having separate desktops, disabling Xinerama will
merge your screens to what you're currently seeing.
Despite this setting being on in your configuration, you're still seeing a
merged setup, but that's because of how the QID has to be configured.
The QID low profile supports merging two outputs together to one logical
screen when using the 'Option "QID" "on"' command in your xorg.conf.
By using the option twice for two separate device sections in your
configuration file, you configured a quadhead setup. Is this what you want?
As far as I understood your posting, you want to have a dualhead independent
setup, is that right?
To achieve this goal, you could try to comment out the 'Option "QID" "on"'
in your device section and see how it fairs.
Also at login screen the two monitor are joined so the username/password
field is in the midle of the two monitor.
This issue should be gone with the above mentioned changes to your
configuration file, but please - after you made the changes - attach
the generated /var/log/Xorg.0.log file to your next message so that I
can see if the changes had any effect on your configuration.
Another problem is SAX, that crash in /usr/share/sax/init.pl line 617 when
I try to start it from command line.
Personally I don't use SuSE and therefore I don't use SAX, so I can't help
you out of the box with this issue, _BUT_ you won't need SAX for
configuring your Matrox graphics card because SAX can't configure it
(currently, no proprietary distribution specific configuration tool can handle
the Matrox P-series cards well because the drivers aren't shipped on the
CDs and Matrox doesn't care about being included in such scripts) so
simply ignore this error and don't use SAX on this system.