New monitor only displays 800x600

[Jamie Kerwick]

Hi there,

I have got a new monitor, a Iiyama Prolite E1900S.
Previously I had a 17" HP Monitor working perfectly in 1280x1024.

But when I swapped that out for the new Iiyama monitor all I get is 800x600.
In my /var/log/Xorg.0.log file I have some entries indicating an error
with monitor setup (CRT-0 is my 19" monitor):

(II) NVIDIA(0): Assigned Display Device: CRT-0
(WW) NVIDIA(0): No valid modes for "1280x1024"; removing.
(WW) NVIDIA(0): No valid modes for "1024x768"; removing.
(WW) NVIDIA(0): No valid modes for "832x624"; removing.
(WW) NVIDIA(0): No valid modes for "800x600"; removing.
(WW) NVIDIA(0): No valid modes for "720x400"; removing.
(WW) NVIDIA(0): No valid modes for "640x480"; removing.
(WW) NVIDIA(0):
(WW) NVIDIA(0): Unable to validate any modes; falling back to the default mode
(WW) NVIDIA(0):     "nvidia-auto-select".
(WW) NVIDIA(0):
(II) NVIDIA(0): Validated modes:
(II) NVIDIA(0):     "nvidia-auto-select"
(II) NVIDIA(0): Virtual screen size determined to be 800 x 600

How do I setup my system to use the correct display mode? Do I need to
enter some modeline information for my display ? If so how do I do it
& where do I get the info from?

The only info about my monitor in /etc/X11/xorg.conf is:

Section "Monitor"
        Identifier      "Generic Monitor"
        Option          "DPMS"
EndSection