Netbeans refuses to add component?

OK so I've got two plotter widgets that I wrote, which are simple JPanels extend for some real time data plotting.  They're only slightly different, but I'm able to add one to the palette and use it in my GUI, while the other one, I can add it to the palette but when I click it to add it to the GUI, netbeans just silently fails.   I don't understand why it's doing this, the second widget is practically a clone of the first, except for some minor changes.  Netbeans produces no errors whatsoever, it just doesn't let me add the  widget...  Has anyone seen this behavior before?