http://www.hacknot.info/hacknot/action/showEntry?eid=76 has an excellent rant about the problems of visual editors (aka GUI builders).
While he talks specifically about Java, the same holds true for all of them. And yes, that means Visual BASIC and Delphi as well, languages which traditionally are seen as almost purely visual.
I've done several midsized Delphi applications and in all of them I ended up writing custom code to manipulate the screen layout and content on the fly, something GUI builders have always promised to make a thing of the past but fail to deliver.