I recently had to upgrade to the R2010b release and now I am having problems with passing handles to the objects created in the Gui Layout. It is a lot of code (a large layout with speed issues as Dani mentioned above.) I will show what is relevant IMHO.
function gui = createInterface()
% Create the user interface for the application and return a
% structure of handles for global use.
gui = struct();
gui.aDetailPlotB = uiextras.Panel('Parent', aDetailPlot, 'BackgroundColor', 'w', 'BorderType', 'none');
In another function file, the gui structure is passed as an argument and then we come down to: