A few days ago I installed Ubuntu 12.04 32bit Desktop. It recognized my hardware without a problem (at least that I know of) and all worked fine.
I left my system running (it is at work) through the night because it is also working as a database server and when I came today to work the resolution was 1024x768 (the monitor recommends 1920x1080) even though in the Display section of the System Settings it was recognized as BenQ, and no higher resolution was offered. After a restart, the monitor name changed from BenQ to Unknown. This is a desktop computer. I also installed gtk-redshift and f.lux.

I checked Additional Drivers to see if there is something I can install but it didn't find anything. I tried to Google it but I didn't find anything about a monitor stopping being recognized after it was already working. I did enable some PPAs yesterday, namely webupd8, mozillateam/thunderbird-stable and some other, and I also followed the instructions to patch the NotifyOSD to be more friendly:

sudo add-apt-repository ppa:caffeine-developers/ppa

sudo add-apt-repository ppa:leolik/leolik 

sudo apt-get update

sudo apt-get upgrade

sudo apt-get install libnotify-bin

pkill notify-osd

sudo add-apt-repository ppa:nilarimogard/webupd8

sudo apt-get update

sudo apt-get install notifyosdconfig

I now purged both caffeine-developers and leolik PPAs in the hope it will help, but no change. Has there been a change in the packages that could introduce this problem?
Any help will be very appreciated :-)

Omri