100% opacity white colour in slot affects bump map

[stevesideas]

A strange thing is happening. I have a book cover where I have used opacity to create the binding holes. The composite layer in the opacity map combines a white colour with a gradient ramp tiled to create the holes. Even if I only have full 255,255,255 RGB in the opacity slot the bump amount is affected. Is this a bug ?

[hermit.crab]

Best you send a scene and some screenshots with the issue and the desired result to support@chaosgroup.com so we can take a look. Mention this thread in the e-mail as well.