Sorry to ask about three issues in one question, but for all I know they are related.
I have a desktop running 11.10, I upgraded it from 11.04 (I think) a while ago, but haven't used it seriously until now, and it seems to be pretty broken.
Firstly, if I try and edit software sources in Synaptic, I get a message saying 'The repository information has changed. You have to click on the "Reload" button for your changes to take effect'. Reloading doesn't help (the message just appears again, and I can never get to the software sources menu), but
apt-get update doesn't report any problems, and I can still update and install software.
Secondly, I have an ATI Radeon HD 5800 GPU, and Ubuntu doesn't seem to think the driver is installed. System Info says 'Graphics VESA: CYPRESS', and the Additional Drivers dialogue offers the FGLRX driver and post-release updates FGLRX driver, saying neither is activated (I definitely had the driver working at some point, probably before I upgraded). If I try and activate the FGLRX driver, the installation process seems to work, but after I restart nothing has changed [EDIT: actually, something does change - Additional Drivers now thinks this driver is installed, but System Info still says vesa]. If I activate the post-release updates version, I get a message saying 'Sorry, the installation of this driver failed. Please have a look at the log file for details: /var/log/jockey.log'. However,
sudo apt-get install fglrx-updates fglrx-amdcccle-updates tells me that both are already installed, and the Catalyst Control Center seems to work correctly. Also, Unity 3D does seem to be working (at least I get the 3D version of the dash bar). I'm guessing this problem could be because of the issue with software sources?
Finally, the Unity plugin seems to be missing from the CompizConfig Settings Manager, though I suppose this could be because of the weirdness with the graphics drivers?
Is there likely to be a way of fixing all this, or should I just reinstall Ubuntu (I haven't had good experiences with distribution upgrades in the past)?