I have a 50 frame shadow pass sequence. When I view the frames within mplay the alpha channel only appears at frame one.

However, the alpha is correct for the full sequence.

I can confirm mplay weirdness when I view within Houdini using a fileIN , the alpha is correct for the full frame range.

I'm using window7/64.

I had a similar problem when I tried to convert *.pic (picnc) sequence to *.tga with Mplay. Alpha channel only appeared at frame one. Rendering *.pic with 8 bit depth instead of 16 solved this problem - alpha was correct in full sequence.