Someone who's had the exact same symtoms would be be your best advisor and that won't be me. However, since nobody has replied, I'll bump this thread along.
Originally Posted by casp3r
My experience with Linux is very fresh and inexperienced.
To diagnose the problem, I suggest you take the opportunity to get acquainted with the log files that the system keeps. You can view them with a text editor or from a terminal (some require that you be root or use sudo) using the command "less".
A simple one ithat you can view without being root is ".xsession-errors", which is in your home directory. It's a so-called "hidden file" since it's name starts with a period.
There are many log files in the /var/log directory. Some important ones are /var/log/messages, /var/log/gdm/:0.log, and /var/log/Xorg.0.log.
You won't understand most of what's in the logs and it is normal to find many reports of warnings or even errors in the logs. What you should look for is a message about something failing to open a file and then using some default file instead. If you find such messages, post them and perhaps someone can figure out the problem.
Of course, some problems are not fixed by logical diagnosis. Instead they are fixed by "replacing random parts", which in operating system repair usually involves uninstallinga and re-installing things.