The names of my folders and the menus are not displayed correctly (even the tabs names in firefox). A lot of letters are missing. When cross over with the mouse pointer, part of them are correctly displayed. Contrary, the content of askubuntu site, for example, is displayed correct. It does not always happens, usually a restart solve the problems for a while. I have Ubuntu 14.04. I don't know how to tag this question, so I'll mark it as display related, even though is not really this.