Getting 1280x1024 in Jaunty with GeForce4 MX 420 card

Yesterday I installed Ubuntu 9.04 (Jaunty) on my old Dell Desktop which has a GeForce4 MX 420 video card.
However, despite installing the 96.43.10 legacy driver, I couldn't get Ubuntu to boot into my preferred 1280x1024 resolution. Instead it seemed to be defaulting to 1024x768.
Nevertheless, by going to System >> Administration >> Display, I was able to use the nVidia dialog to get 1280x1026_60.
However, when I asked it to modify the /etc/X11/xorg.conf file, it seemed to error-out saying that it couldn't create a backup of the xorg.conf file. Strange.
Nevertheless, it did provide a button to show what the changed xorg.conf would look like. So, I copied it and made a new xorg.conf manually (of course, making sure to keep a renamed version of the old xorg.conf as these experiments can easily lead to X not starting).
However, rebboting with this xorg.conf, although it did provide the required 1280x1024 on boot, it seemed to interfere with the 3D effects as AWN just produced a white band, Yakuake had no command prompt and a terminal was unwritable.
In any event, there seemed to be just one line in the suggested xorg.conf that was of relevance to the production of the required resolution. This was

Option "metamodes" "1280x1024_60 +0+0"

So, I added this to the screen section of the original xorg.conf and rebooted. Success!!, this worked fine.
Note, however, that in former versions of Ubuntu, the 1280x1024 was made available with the foolwoing line in xorg.conf:

Modes "1280x1024" "1024x768"

So, this seems now tto have been replaced by the "metamodes" line.
Just for completeness, I'm going to print all three versions of xorg.conf that feature in this post:
First, the original (or default) version that didn't allow Ubuntu to boot into 1280x1024

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
DefaultDepth 24
Option "AddARGBGLXVisuals" "True"
EndSection

Section "Module"
Load "glx"
EndSection

Section "Device"
Identifier "Configured Video Device"
Driver "nvidia"
#Option "NoLogo" "True"
EndSection

Now, here's what nVidia seemed to be suggesting but, for some reason, was not able to install it. In any event, it gave serious problems as I've already mentioned.

Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
EndSection

Section "Module"
Load "glx"
EndSection

Section "ServerFlags"
Option "Xinerama" "0"
EndSection

Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection

Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "DELL E771a"
HorizSync 30.0 - 70.0
VertRefresh 50.0 - 160.0
EndSection

Section "Device"

#Option "NoLogo" "True"
Identifier "Configured Video Device"
Driver "nvidia"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce4 MX 420"
EndSection

Section "Screen"
Identifier "Default Screen"
Device "Configured Video Device"
Monitor "Configured Monitor"
DefaultDepth 24
Option "AddARGBGLXVisuals" "True"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "TwinView" "0"
Option "TwinViewXineramaInfoOrder" "CRT-0"
Option "metamodes" "1280x1024_60 +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection

And finally, here's the modified verion of the original xorg, that actually works fine.

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
DefaultDepth 24
Option "AddARGBGLXVisuals" "True"
Option "metamodes" "1280x1024_60 +0+0"
EndSection

Section "Module"
Load "glx"
EndSection

Section "Device"
Identifier "Configured Video Device"
Driver "nvidia"
#Option "NoLogo" "True"
EndSection