From your xorg.conf:
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
Virtual 2048 768
IMHO, your screen resolution can't be bigger than your virtual screen size. Somewhere you must have requested to write such a nonsense in you xorg.conf ;-)
You could try:
Remove the three lines "SubSection...EndSubSection"
Run without a xorg.conf at all (move it away)
There may be other bogus configuration files which I didn't see though.