GridBagLayout allows to override column/row weights, column minimum widths and row minimum heights though columnWeights, columnWidths, rowHeights, rowWeights fields. Unfortunately, it is not possible to set these fields in NetBeans GUI builder.
columnWidths and rowHeights allow to build non-degenerated empty columns/rows that can serve as gaps between components.
columnWeights and rowWeights provide a better control over the resizing of the layout (which is otherwise based on hazy implementation burried in the depths of GridBagLayout).
Modified files: http://hg.netbeans.org/jet-main/rev/09b70224b38c