VLayout setMargin still has a margin

[haighis]

I am trying to set the margin of VLayout to 0 in order to have the control flush with the browser window but there is still at margin/spacing.

Here is a screen shot of the issue: http://www.johnhaigh.com/MarginScreenCapture.jpg

SmartGWT Version: 2.3
Browser Version: FireFox 3.6.9

Here is the sample code surrounding the issue:

mainLayout = new VLayout();        
mainLayout.setMargin(0);

Thanks,

John Haigh