Thanks for your reply, I had almost given up...
I get these weird signs in 'the Gnome environment', if I can call it that, when PT Sans is set as Application font. As you see in the picture, all folder names containing æøå
become like this. The same happens if I try to create a folder (or file, for that matter). It also occurs in Empathy.
As for X-Chat: When the Application font overrules the font settings, I get weird characters there also. When I turned that off, however, and specifically chose PT Sans for it, I didn't get weird characters anymore.
So, what all these have in common is that it is when PT Sans is set as a standard font I get these characters.
Could it have something to do with the way I installed the font? First, I just put it in the .font folder in Home, then I did this:
Originally Posted by Ubuntu Wiki
There are various locations in GNU/Linux in which fonts can be kept. These locations are defined in /etc/fonts/fonts.conf; standard ones include /usr/share/fonts, /usr/local/share/fonts, and /home/<username>/.fonts (where <username> is your user name).
The easiest way to install a truetype font is to press alt-F2 and enter the following code (this will open nautilus in the right directory):
gksu nautilus /usr/share/fonts/truetype
Then create a new directory, name the directory whatever you like (choose a name that you remember if you ever need to backup your fonts personal fonts). Copy the fonts into that directory and finally rebuild the font information files by pressing alt-F2, mark 'run in terminal' so you can see the progress and entering the following code:
sudo fc-cache -f -v
I did not remove the original files I had put in the .font folder prior to that.
I'm running an English interface, but it has never been an issue with Norwegian characters before.