I have the following wiki code in my pages:

 !Icons^d.png!!Icons^t.png!!Icons^p.png!

This works fine confluence 2.9 (it shows a blank and 3 images)
But in 3.1 this is broken: See it here

It works when I add a space after  

  !Icons^d.png!!Icons^t.png!!Icons^p.png!

So the first image is not rendered correctly, it seems like the preceding   is breaking the recognition of the image... This bug is problematic because this code is contained in lots of pages....