Filter Gallery image problem

[Coastwalker]

I'm using Photoshop 8 on a Mac with OS 10.6.4. I have an image to which I'm trying to add specific effects from the Filter Gallery. However the image doesn't appear in the FG preview window for some effects. All I see is a white window. It does appear in the window for other effects, and those effects can be applied. The image is a TIFF that has been flattened. I had also saved it as a jpg, but that didn't make any difference. Of course, the effect I want to use (Plaster) is one of those for which my image doesn't show.

Any thoughts on what I can do to correct this problem?

Thanks!

[Ultiman]

if the image is to big perhaps its viewing it zoomed in
try zooming out in the FG window

[Coastwalker]

Thanks. I though of that too, and tried reducing the image down to 50%. It didn't change anything: The image still showed when some Filter Gallery effects were selected, but not when others were selected.