diff -up ./build.xml.tests-headless ./build.xml
--- ./build.xml.tests-headless	2009-11-09 10:35:40.000000000 +0100
+++ ./build.xml	2009-11-09 10:36:06.000000000 +0100
@@ -466,6 +466,7 @@
       <jvmarg value="-Djna.protected=true"/>
       <jvmarg value="-Djna.builddir=${build}"/>
       <jvmarg value="${vmopt.arch}"/>
+      <jvmarg value="-Djava.awt.headless=true"/>
       <classpath><path refid="test.runpath"/></classpath>
       <formatter type="xml"/>
       <batchtest todir="${results.junit}">