All text looks like a UPC code. So far I've only see this occur on the Radeon 7200 series using Mesa 6.5.2. Picture is located here:
http://vaalnor.mine.nu/vaalnor/videoglitch/fontdisplay2.png.
Solution: Font multitexturing has been broken, try the following:
Open up the file Planeshift3D/data/config/r3dopengl.cfg in a text editor, and find this line:
Video.OpenGL.FontCache.UseMultiTexturing = yes
and change yes to no.
For a more thorough listing of graphical glitches, please feel free to reference:
http://vaalnor.mine.nu/psdoc/?q=node/39.