After upgrading to Natty and the 2.6.38-8 kernel I could no longer obtain the 1920x1080 resolution available in Maverick with 2.6.35-22. In fact the boot occasionally hung. However, after selecting the remaining 2.6.35-22 kernel, the high resolution was available.
I then made the mistake of completely reinstalling, but could never get the higher resolutions with 2.6.38-8, no matter what I did. e.g. trying the nvidia proprietary driver, creating an xorg.conf. Even from the command line using
xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync xrandr --addmode DVI-I-1 1920x1080_60.00 xrandr --output DVI-I-1 --mode 1920x1080_60.00
all I would get would be a blank screen and the monitor reporting no input. (Low resolutions displayed fine with xrandr.) I could actually add the 1920x1080 to the already existing probe-reported resolutions in the pool of available resolutions, but choosing it would give the blank screen. In the end I installed the 2.6.35-22 kernel again. The high resolution is back.
For a while there, staying up all night and trying many things, I thought that a new video board or monitor might be needed, but deep down, I knew that they were both OK.
My question is - "Is this some bug involving the latest kernel, that will go away, or if this persists in future kernels, is there a way to make sure that I can keep my native resolution?"