Particles wont fade out with image assigned

I'm having a weird problem where my particles wont fade out if I have an image assigned. If I set it to no image, if fades out fine. Anyone else seeing this? I'm using a .png with alpha.
They seem to kinda fad down a little, but not smoothly, and only to like 50%. I made a test map with just a new particle system in it, and I get the same thing.
They seem to kinda fad down a little, but not smoothly, and only to like 50%. I made a test map with just a new particle system in it, and I get the same thing.
Comments
Also, we really need the ability to animate the particles images.