I'm using Java and NetBeans to create an application and I seem to be getting some varying results when it comes to making and changing the GUI using the editor.
My design in the editor looks like this:

When I click on the icon to give me a demonstration of what it would actually look like I see this:

Notice that the panel to the right of the GUI has moved down and pushed the text box down as a result.
Now when I come to run the application itself I see this:

I may be too used to the way in which the Visual Studio IDE works in the fact that everything generally stays where you put it, am I missing some sort of hidden trick or property that is throwing everything off?
Thanks for your time.
Edit:
Code for the components - http://pastebin.com/FHF2fBEw