Weird Formatting Error...

Hello SwiXML Folks,

I'm having a really odd formatting error and was hoping someone could  
help me out.

I've got a pretty basic UI defined by the following XML:

<?xml version="1.0" encoding="UTF-8"?>

<frame name="mainframe" layout="BorderLayout" size="1024,700"  
title="SpatioTemporal Explorer" resizable="false"  
plaf="com.sun.java.swing.plaf.windows.WindowsLookAndFeel">

     <panel Layout="GridLayout(1,1)" constraints="BorderLayout.NORTH"  
Border="EtchedBorder">
         <textpane id="messageArea" editable="false"/>
       </panel>


     <panel constraints="BorderLayout.WEST" Border="EtchedBorder"></ 
panel>
       <panel constraints="BorderLayout.EAST" Border="EtchedBorder"></ 
panel>

       <panel id="aquariumPanel" Layout="BorderLayout"  
constraints="BorderLayout.CENTER" visible="true"  
Border="EtchedBorder" />

       <panel Layout="GridBagLayout" constraints="BorderLayout.SOUTH"  
Border="EtchedBorder">
           <tabbedpane>
                   <textfield id="dataArea" name="Data"  
editable="false"/>
                       <gridbagconstraints id="gbc_2"  
insets="0,0,0,0" gridx="0" gridy="0" ipadx="1024" ipady="-30"  
weightx="100" weighty="0"/>
                   <panel id="clusterArea" name="Clusters"/>
                       <gridbagconstraints id="gbc_2"/>
                   <panel id="navigateArea" name="Navigation"/>
                       <gridbagconstraints id="gbc_2"/>
           </tabbedpane>
       </panel>

</frame>

A screenshot of it can be seen here: http://tsunami.geo.ed.ac.uk/ 
~s0454395/pic.png

What is happening is the UI is created from the XML as it should, and  
everything is swell. I have a Canvas3D in teh aquariumPanel which  
displays perfectly (see screenshot.) Everything is swell until I add  
some more graphics to my Canvas3D and suddenly my bottom panel  
containing the tabbedpane gets compressed by my middle panel  
(aquariumPanel).

Here's a screenshot: http://tsunami.geo.ed.ac.uk/~s0454395/pic2.png

I'm trying to figure out how to prevent this. Does anyone know how?  
I've tried specifying the size explicitly in my aquariumPanel  
declaration and it doesn't work.

Lastly, where do the bounds parameters come into play? I can't quite  
figure out what they do. Would they help me in any way with this  
problem?

Thanks.
./dylan