Confusing: Canvas image working in function but not in class

[Mudcat]

I have an image that displays on a canvas that works unless I put the
same code in a class. I can't figure that out. Here's what works:

    def uts5100(self):
        self.screen = Toplevel( self.master )
        self.screen.geometry("+100+50")
        self.screen.grab_set()
        self.screen.focus_set()

        self.screenType = "uts5100"

        self.canvas = Canvas(self.screen)

        self.canvas.create_image(20, 20, image = self.empty5100,
anchor=NW, tags = "chasis" )

        self.canvas.pack()

The image is opened in another function:

    def openImages(self):
        self.empty5100 = ImageTk.PhotoImage( Image.open("Images/" +
"5100empty.bmp") )


However if I do the same thing, but in it's own class, the image does
not appear:

    def uts5100(self):
        sys5100 = UTS5100( self.master )

class UTS5100:
    def __init__(self, master):
        self.master = master
        self.openImages()
        self.draw()

    def openImages(self):
        self.empty5100 = ImageTk.PhotoImage( Image.open("Images/" +
"5100empty.bmp") )


    def draw(self):
        self.screen = Toplevel( self.master )
        self.screen.geometry("+100+50")
        self.screen.grab_set()
        self.screen.focus_set()

        self.screenType = "uts5100"

        self.canvas = Canvas(self.screen)

        self.image = self.canvas.create_image(20, 20, image =
self.empty5100, anchor=NW, tags = "chasis" )

        self.canvas.pack()


They are called from a button that when pressed creates the window
where the image is supposed to appear. Obviously there is something
that I am missing when putting this window into it's own class, but I
can't figure it out.

Anyone got an idea why this is happening?

Thanks