Previews 'black'

[Sventek Profile]

With some of the previews, all I see is a quick initial application, but then the image is entirely black. It stays that way if the effect is applied. Even with the master fade, all that happens is that the image fades in and out of blackness. This even occurred when I did a partial selection. The entire image was made black.

[admin]

Can you tell me what the names of the effects that come out black are?

Thanks

Tony