[magick-users] convert "dispose" option problem

[rhubarbpie at poetworld.net]

I'm attempting to create an animated gif using "convert @InputFiles.txt 
-dispose 2 -loop 0 Presentation.gif".  Although the animation is 
generated, "-dispose 2" has no effect.

In explanation, I want the animation to show a fresh image without 
overlap.  However, the gif overlays the images.  I've generated gif's 
with "-dispose 2" several times without problem and the individual gif's 
look fine.  What the heck?  I assume this is something simple I'm 
overlooking.  Thoughts?