Initially the splash screen stayed black and nothing happend. I removed the splash and then studied the startup log to try and spot where it goes wrong. Safe mode works fine.
The first two lines in the Call Trace is:
nv50_cursor_hide0x6b/0x55 [nouveau] ? nv50_evo_channel_del+0x62/0x70
Does "nv" refer to Nvidia? Meaning there are issues with the graphics driver? I have not installed or done anything with nvidia drivers before the crash. I have though installed software that Ubuntu Software Center recommends to me, thats about it.