Hi All,
I have a HP Microserve N36L which i've been running for about 3 years.
It's been running 10.10 all this time, so I thought it was about time to update to the latest LTS release of Ubuntu server (12.04)
So I performed the upgrades 10.10 -> 11.04 -> 11.10 -> 12.04. I have a big 27" 2560x1440 monitor with vga input fed by the n36l.
Up until the last release upgrade the output has been fine and I've been able to see a login screen after boot.

When I rebooted into 12.04 I saw the HP boot screen and the grub selection screen, after that though it goes dark and the login prompt doesn't appear.
I couldn't understand what was going on so I dug out an old 19" 1280x1024 monitor. Switched the cable from the 27" to the smaller monitor and got a signal out of range error. I then rebooted the box from a ssh session with the cable plugged into the smaller monitor and everything was fine, i could see the login screen.

Does anyone know what I need to do to get the login screen appearing again on my big monitor, as i'd rather not have two monitors sitting in the room.
Is it as simple as setting nomodeset in the /etc/default/grub GRUB_CMDLINE_LINUX_DEFAULT="nomodeset"