animated userpane for vista.

as you can see, there is a white endging around the edge of the animation,  before the animation shape was the same as the userpane, containing the fish too.......but the white edging was around the edge of the fish.......so my idea was to rub out the fish ect and the white would go away...........as you can see, it has not and still remains..

any idea why this is happening? and how it can be resolved? i really cant move forward with my skin until a solution has been found........ i only currently have 29 frames....... so i cant see how size would play a part as ive seen much bigger frame sizes used.