I have a very specific problem that has been plaguing me forever, its hard to explain so I'm showing this image:

http://i.imgur.com/A3QEf.gif

As you can see, the one frame carries over into the next frame making an ugly ghosting effect. No matter how many time I erase it, it comes back after I save it. And I need this to be transparent, how can I fix this?

I've tried to look all over the options of this program and I have no idea.