Here is my InDesign CS3 problem and what I've tried so far:
I have a 2 page spread containing photos, text, and shapes. I want to make the shapes opaque, but I can't do this without making the whole spread opaque (the photos and text go opaque as well). I've tried putting objects in different layers, putting objects in frames, locking everything, bringing in the opaque object from both Illustrator and Photoshop. I've also tried updating the program version (which is now 5.0.4), and opening up new documents to try it on. None of this has worked. If anyone has any ideas of how to fix this, I would really appreciate it!
After much trial and error, I think I've found the solution to my problem. I've found that you can't do opacity of an object on top of a grayscale jpeg. You can convert it to a grayscale PDF, TIFF, etc, but grayscale jpegs don't work.
I have been having the same problem with InDesign CS3 but I have no idea how to fix it - unlike you I have NO images on my page, just several frames with fills of different colours, some with text, etc. If I select one frame and change the opacity everything else changes too! Even when I select "isolate blending" or "knockout group".... complete nightmare...
Wondering if anyone found a solution to this issue, I too am having the same problem with Indesign CS4. I tried moving the object to a different spread, reset all of my preferences, tried a new document. Each time I try to change the opacity of one object it changes my photos as well.