storage of gui data fails
===

I save and load gui data as described in the manual using

    function readImage(filename, hObject, handles)
      handles.image.data = imageRGBNoEdge;
      guidata(hObject,handles);

and

    function createHistogram(handles)
      imageRGB = handles.image.data;

which are both called directly after the other

    readImage(imageFile,hObject,handles);
    createHistogram(handles);

However in he second function handles.image is unkown.

    ??? Reference to non-existent field 'image'.
    Error in ==> ui_histogram>createHistogram at 252
    imageRGB = handles.image.data;

But if I call the function a second time it is known???
