I'm sure the card suppoorts it... otherwise you would have had "effect not supported".

Is this using the stock textures from the demo of the shader?? If not, it may be more of a scaling and texture issue.

Many games have multiple effects for fallback to support a wide array of cards. Also, they (the coders) have more flexibility in how they program the effects as they are not limited to the same functions we are right now. They have more control over texture coordinates, the streams, and also multipasses, among other things.