Today, after a crash, I suddenly found all fonts are looking ugly. I had similar experience earlier, but that was with Fedora with Gnome desktop. There, I was unable to solve the problem properly. I got some workaround and compromised with the semi-ugly looking fonts until the further release of Fedora. Here, I won't want to carry the same pain for next few months. So, I search vigorously to get some solid solution but fail to do. Finally, in a forum discussion, I got a comment, which lead me to the solution.
Before providing with the solution, I want clear about my current platform. The problem I faced with my laptop having Ubuntu 11.10 and KDE desktop. The laptop is all Intel even it has the Intel integrated graphics. I also switched the display manager from lightdm to KDM. So, it's all-around KDE system.
In recent past I am facing few unusual behaviors; specially, after upgrading from Ubuntu 11.04 to 11.10. During my KDE session, it often crashes for no visible reason. Few of them happen during Firefox launch, but others, I am still trying to find the cause. After such a crash with no reason suddenly I found that all fonts are looking like skeletons. Especially on Firefox. Web pages are opening with same ugly fonts.
I had previous experience that, this is about anti-aliasing, but I could not be able to reset this correctly. So, the problem remains unsolved. Finally, when I saw a comment in a forum that KDE stores all configuration in hidden files at the home directory. I started searching such configuration files and found two. One file ".fonts.conf" and a folder ".fontconfig". What I simply do is, delete those files and restart Ubuntu. That's it! Everything goes to the same as it was. It makes me so happy that I want to share with all of you right now.
Note: I do not use command line to remove those files. If you prefer command line then the command would be, rm -r .fontconfig; rm .fonts.conf;