ok, I have my ATI Radeon 2400XT working properly for longtime on ubuntus (8.04 - 12.04) and recently when I was trying to update (it installs kernal 3.2.0-31 during that update) every think related to ATI including property drivers (that can be activated from additional drivers) are vanished so AMD catalyst control center is not working (it says no amd graphics card is installed) and when opening [additional drivers] it loads and then a box is appear saying (Downloading package indexes failed, please check your network status. Most drivers will not be available.) after searching for additional drivers the window appear saying (no property driver are used on this system). I don't know what happened really! I don't know how to fix this problem either. help!!