Problemas com iReport

[fabioquaresma]

Olá, estou tentando usar o iReport no ubuntu, mas gera o seguinte erro:

Exception in thread "main" java.awt.AWTError: Cannot load AWT toolkit: gnu.java.awt.peer.gtk.GtkToolkit
at java.awt.Toolkit.getDefaultToolkit(libgcj.so.7)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(libgcj.so.7)
at java.awt.Window.<init>(libgcj.so.7)
at java.awt.Frame.<init>(libgcj.so.7)
at java.awt.Frame.<init>(libgcj.so.7)
at javax.swing.SwingUtilities$OwnerFrame.<init>(libgcj.so.7)
at javax.swing.SwingUtilities.getOwnerFrame(libgcj.so.7)
at javax.swing.JDialog.<init>(libgcj.so.7)
at javax.swing.JDialog.<init>(libgcj.so.7)
at it.businesslogic.ireport.gui.SplashDialog.<init>(SplashDialog.java:1
at it.businesslogic.ireport.gui.MainFrame.main(MainFrame.java:6691)
Caused by: java.lang.ClassNotFoundException: gnu.java.awt.peer.gtk.GtkToolkit
at java.lang.Class.forName(libgcj.so.7)
at java.lang.Class.forName(libgcj.so.7)
at java.awt.Toolkit.getDefaultToolkit(libgcj.so.7)
...10 more

Como solucionar esse problema?