Animated textures possible with GLSL?

I created an image texture with a sequence of images. I activated Blender GLSL materials under the Game menu. But when I step through time, the texture isn’t updated. Am I doing something wrong?

Please,

If a texture could real time show an image sequence or video in GLSL then Blender would be an amazing interactive video compositing software. Right now I put my green screened actors (real people) image sequences into Blender but the actors don’t move when I scrub through time so it is dreadfull trying to interact them with the scene I created in Blender - I have to reload the image. All we need is to enable automatic update in textures so we can see the actors move. Why can’t we do this? Takes too much memory? Can’t we use a dithered or reduced resolution in GLSL realtime preview?