Dear all,
I'm working on a poster (which needs to be delivered tomorrow...), and when attempting to export it as pdf I realized that some transparency was lost.
After quite some time spent trying to figure it out, it turns out that it's most likely because of clipping. Transparent objects in a clipped group loose their transparency when exported, while they keep it if their group is not clipped (e.g. when I ungroup the clipped group).
Please see the file attached. Try to export it as pdf, with all defaults. You should see that the circles on the main map at the top are transparent, while those who belong to a group that was clipped (for instance in the zoomed map of Europe at the top, or in both maps at the bottom).
This looks a lot like a bug to me.