Strange font problem

Hello!

I have a pretty strange font problem, please take a look at:
http://rzinbw.blu.livefilestore.com/y1pfRZV2DNlo31L-eFu8dVppRnIAM4jB2qk16V4heC6O0MF4eEJmVnS76387AN2BJ46S0W4FH4cH_1PfMU-7TuCuA/strange_font.png

As you can see the font is not very nice.
I do not use any special font and have not set it in the code any where, all my Java-apps behaves the same.

I use Mandriva 2009 and I think that the jdk I use to run the apps in is called:
java-1.6.0-openjdk-1.6.0.0
...shipped with mandriva.

Perhaps that jdk doesn not include the standard fonts that is used by Java apps or is it my OS that do not supports the fonts needed by Java.

Any ideas is most welcome.
Best regards
Fredrik