DDD fonts too small to see

Dear DDDers,
As screen resolutions have increased, the default
DDD fonts are becoming increasingly difficult to read
on my Linux Fedora installations. I have tried to
reset the font sizes to no avail. I go to
Edit->Preferences->Fonts->Default Fonts and try to
manually increase the pixel sizes but nothing happens.
Is it an issue with what fonts are
installed and DDD knows about on my system?
How do I get legible font packages installed on Fedora?
Any suggestions?
Thanks in advance,
Charlie
-- 
Charlie Zender, Earth System Sci. & Computer Sci.
University of California, Irvine 949-891-2429 )'(