Binary package hint: xorg
Two bugs:
1) upgrade to the .4 release killed X. The nvidia splash screen would load, and then the system would hard lock. The last log messages (in syslog) had to do with ramping AGP up to 8x...is that done on X init?? I can debug this if you need, since now I have a fix path (I downgraded back to 10.1 to get into x again).
2) (this is dupe, but worth mentioning again) the upgrade nuked my xorg.conf with an autogenerated one. This is just unacceptable. If you search ubuntuforums.org you'll find hundreds of people customizing their xorg.conf -- this is necessary, since the defaults do not perform. The defaults in fact totally break my system, since I have a triple head/xinerama/two card setup. You need to figure out some way of seperating user-modifiable stuff from stuff that can be safely upgraded. Alternatively the upgrade routine should diff the existing xorg.conf with a proposed xorg.conf, and notify the user.
I know it's bad practise to do this, but *bump*!! I just tried the upgrade again, and it hard locks my machine. The update is buggy. Please fix it. If you need more information I'm happy to run some tests.