I upgraded ubuntu to 12.04 and ended up with a blank screen of death. Finally, figured out that xorg was not installed and that to install xorg, I have to downgrade xserver-xorg-core. I did that and I am able to log in, however, I don't see any change. The login screen shows 11.10.
On looking into Software Sources, I find the repositories point to Oneiric and not to Precise. However, "lsb_release -a" tells me it is Precise.
Can someone guide as to how to get the Precise repositories and get it properly upgraded.