To reproduce:
1) Unzip the attached NB project (GridPaneTestV3.zip)
2) Setup project with FX JAR path
3) Run
     -> a window displays a GridPane with 2 cols and 3 rows (see GridPaneV3.png)
4) Click 'Append a Row' button
     -> a new RowConstraints is added to the GridPane
     -> GridPaneDesignInfo.getRowCount() is displayed in terminal : 4 => OK
     -> GridPaneDesignInfo.getCellBounds() is invoked for all the cells of the first column
           -> for cells (0, 0), (0, 1), (0,2) => OK
           -> getCellBounds() throws ArrayIndexOutOfBoundsException: 3 for cells (0, 3) => BUG


Caused by: java.lang.ArrayIndexOutOfBoundsException: 3
at javafx.scene.layout.GridPaneDesignInfo.getCellBounds(GridPaneDesignInfo.java:93)
at test.MainWindow.onDelete(MainWindow.java:38)
... 42 more


Tested with:

     [echo] Current SDK: Product: javafx-2.2.0beta
     [echo] Platform: macosx-universal
     [echo] Build-Number: 121
     [echo] Build-ID: 2012-07-03_20-48-05