A

      sudo apt-get remove ttf-gujarati-fonts

as suggested in http://intellij.net/forums/thread.jspa?forumID=27&threadID=189420 didn't help it.

Running with -Djava.awt.headless=true as suggested in 
https://lists.ubuntu.com/archives/ubuntu-users/2006-May/079549.html
doesn't help it either. It throws the following exception then:

muelli@xbox:~$ sh /home/muelli/svn/tr-2.0.epsilon/bin/../platform6/lib/nbexec --jdkhome '' --branding thinkingrock --clusters /home/muelli/svn/tr-2.0.epsilon/bin/../thinkingrock:/home/muelli/svn/tr-2.0.epsilon/bin/../ide7 --userdir /home/muelli/.thinkingrock/dev -J-Xms64m -J-Xmx256m -J-Dnetbeans.logger.console=true -J-ea -J-Djava.awt.headless=true
-------------------------------------------------------------------------------
>Log Session: Saturday, March 29, 2008 5:08:00 PM CET
>System Info: 
  Product Version         = ThinkingRock 2.0 Epsilon
  Operating System        = Linux version 2.6.24-12-generic running on amd64
  Java; VM; Vendor; Home  = 1.6.0_05; Java HotSpot(TM) 64-Bit Server VM 10.0-b19; Sun Microsystems Inc.; /usr/lib/jvm/java-6-sun-1.6.0.05/jre
  System Locale; Encoding = de_DE (thinkingrock); UTF-8
  Home Dir.; Current Dir. = /home/muelli; /home/muelli
  Installation; User Dir. = /home/muelli/svn/tr-2.0.epsilon/thinkingrock:/home/muelli/svn/tr-2.0.epsilon/ide7:/home/muelli/svn/tr-2.0.epsilon/platform6; /home/muelli/.thinkingrock/dev
  Boot & Ext. Classpath   = /usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/resources.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/rt.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/jsse.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/jce.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/charsets.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/classes:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/ext/dnsns.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/ext/sunpkcs11.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/ext/sunjce_provider.jar:/usr/lib/jvm/java-6-sun-1.6.0.05/jre/lib/ext/localedata.jar
  Application Classpath   = /home/muelli/svn/tr-2.0.epsilon/platform6/lib/boot.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/org-openide-modules.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/org-openide-util.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/boot_ja.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/boot_pt_BR.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/boot_zh_CN.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/org-openide-modules_ja.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/org-openide-modules_pt_BR.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/org-openide-modules_zh_CN.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/org-openide-util_ja.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/org-openide-util_pt_BR.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/lib/locale/org-openide-util_zh_CN.jar:/usr/lib/jvm/java-6-sun/lib/dt.jar:/usr/lib/jvm/java-6-sun/lib/tools.jar
  Startup Classpath       = /home/muelli/svn/tr-2.0.epsilon/platform6/core/core.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/org-openide-filesystems.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/locale/core_pt_BR.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/locale/org-openide-filesystems_zh_CN.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/locale/core_zh_CN.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/locale/org-openide-filesystems_ja.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/locale/org-openide-filesystems_pt_BR.jar:/home/muelli/svn/tr-2.0.epsilon/platform6/core/locale/core_ja.jar:/home/muelli/svn/tr-2.0.epsilon/thinkingrock/core/locale/core_thinkingrock.jar
-------------------------------------------------------------------------------
java.awt.HeadlessException
	at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:159)
	at java.awt.Window.<init>(Window.java:407)
	at java.awt.Frame.<init>(Frame.java:402)
	at org.netbeans.core.startup.Splash$SplashWindow.<init>(Splash.java:506)
	at org.netbeans.core.startup.Splash.showSplash(Splash.java:85)
	at org.netbeans.core.startup.Main.showSplash(Main.java:428)
	at org.netbeans.core.startup.Main.start(Main.java:371)
	at org.netbeans.core.startup.TopThreadGroup.run(TopThreadGroup.java:96)
	at java.lang.Thread.run(Thread.java:619)
java.awt.HeadlessException
	at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:159)
	at java.awt.Window.<init>(Window.java:407)
	at java.awt.Frame.<init>(Frame.java:402)
	at org.netbeans.core.startup.Splash$SplashWindow.<init>(Splash.java:506)
	at org.netbeans.core.startup.Splash.showSplash(Splash.java:85)
	at org.netbeans.core.startup.Main.showSplash(Main.java:428)
	at org.netbeans.core.startup.Main.start(Main.java:371)
	at org.netbeans.core.startup.TopThreadGroup.run(TopThreadGroup.java:96)
	at java.lang.Thread.run(Thread.java:619)
muelli@xbox:~$