The following class implements a chatGUI. When it runs okay the screen looks like this:
Fine ChatGUI http://img21.imageshack.us/img21/7177/rightchat.jpg
The prob
The problem might be the layout manager you're using.
You have a GridBagLayout
for all the components. Try adding the bottom component in their own panel instead of align them with the history text area.
Something like:
JScrollPane history = new JScrollPane( new JTextPane() );
JPanel inputClearSavePane = new JPanel();
// layout the input, clear save button
getContentPane().add( history );
getContentPane().add( inputClearSavePane, BorderLayout.SOUTH );
And see if that helps. edit
BTW, it works on Mac
Linux
And windows: