We try to use swing.properties or specify -Dswing.defaultlaf=com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel. on the syncroSVNClient.sh, but it doesn't work. Cloud you tell us how to change the Look and Feel in Ubuntu ?
You should use a combination of look and feel, style and theme from the set available from menu Options -> Preferences -> Global. The floating and dockable views cannot work with any general Swing look and feel.