I just installed the updates (sudo aptitude upgrade, not dist-upgrade!) on a computer that is usually not connected to the internet. It uses Xubuntu 14.04.2 LTS (trusty) with an ATI Radeon HD 6550D video card and the fglrx-updates driver.
During installation of the updates, it asked me if I want new configuration files or if I wanted to keep the old ones. I choose to keep the old ones just to be sure. After rebooting however, my screen resolution is stuck at 640x480. It can't be changed from the list in the Display settings.
So my question is: how can I get my normal 1440x900@60hz resolution back? Thanks in advance for an answer.