I'm brand new to Ubuntu (and Linux in general) and have set up 12.10 to dual boot (along with Win7). Everything was going OK, but when I installed the updates and rebooted, I found that, after choosing to boot into Ubuntu, I got a flashing purple screen with no login. I was able to reboot again and got into Ubuntu by choosing the advanced option, with boot into safe mode.
When I checked to see what was going on with the display in the settings menu, my monitor now comes up as a laptop monitor, whereas it was previously identified as a 19" Dell monitor before the update.
Keeping in mind that I'm brand new to Ubuntu and the world of Linux, what is likely to be the problem and what can I do about it?
Update (21:15 GMT, 2/16/13)
I've gone ahead and reinstalled 12.04, but the problems persist. I can get everything working OK if I open Ubuntu using recovery mode, otherwise I get the flashing purple screen. I have, however, gotten the monitor to be detected as a Dell 19" rather than a laptop screen. Any other ideas?