When editing a gradient using the gradient editor, as I move my mouse over the gradient area onto the slider items to, the bar flickers up and down.  As it does so, some text is shown and hidden.

When the gradient editor starts out (in it's own window), it just has the label (Gradient Editor), a text box (FG to BG (RGB)), the gradient area, the instand update check box, and the load/save/zoom buttons.

As I move my mouse (from top to bottom) onto the gradient area, it shinks and some extra text is shown (Position, RGB, HSV, Intensity, Opacity). As it passes over the slider area, the text is hidden and the gradient area returns to the normal size.  This is where the bouncing/flickering begins.  Since the mouse is back over the gradient, it shows the text again, and then hides it again, etc as the mouse is moved.

System Specs:
Windows 2000 SP4
GIMP 2.2.12
GTK+ 2.8.18

I've had this problem on other Windows as well.