I have a Kubuntu 10.04 system that I use for software development. I've had it for quite a while and things have been working well - no unexplained glitches. I've got it setup so that it automatically boots into the KDE gui.
A few days ago, it stopped initializing the gui and just drops me into a character mode screen. I can login there, but no graphical interface. I've got the nvidia drivers installed and have two monitors configured which has also been working fine.
dmesg has nothing that seems relevant. I've tested the graphics card and it seems to be just fine, as is my other hardware. I may have done a security update recently, but don't know which ones as I rarely reboot this machine.
What should I be looking for or trying out to resolve this issue?