Gif image thumbnail not displaying

I have two images sitting on my BumpTop - a .jpg and a .gif - but only the .jpg shows the actual image, the .gif is just a generic 'picture' icon. This happens regardless of how much I shrink or grow the icon.

update - I just noticed that after double-clicking another graphic to do the 'zoom in slideshow' thing, when I zoomed back out, the .gif thumbnails were displaying like normal, although one seems to be in the wrong aspect ratio.