Navigation stops working after changing image

[chaoaretasty]

Everytime I change the selected source image the update doesn't completely clear the previous one. Each new image leaves a "Randomise" in the controls at the top and messes up the control bindings, after the first image change up and down now change the x-axis, left and right do nothing and randomise only affects the x-axis, on the second image change keyboard and randomise fail (the sliders always work).

[skratchdot]

@tiborsaas - I just happened to look at this today, and notice I introduced a bug. Figured I'd fix it. Didn't spend too much time on the original feature, so missed this code path. Sorry about that...