Structure Chooser dialog is smaller each time it is opened

Height is saved as "structureChooser.height" in a static Hashtable.
It is saved as the value of
- JTabbedPane pnl_filter
and restored as preferred height of
- JTabbedPane pnl_filter
- JScrollPane scrl_foundStructures
- JScrollPane scrl_localPDB
and as the height of the JInternalFrame.
Net result seems to be that it is a bit shorter each time it is opened.