See attached screenshot, the OOo gulls should be light-blue rather than black. It appears that the Z-ordering in Evince _is_ correct, just the colors are wrong. Also look at the OpenOffice.org Conference logo in the bottom left, the transparent color is wrong in Evince...
Created attachment 115793 [details] Comparison of Evince and Acrobat Reader
Created attachment 115794 [details] Problem presentation PDF
Fixed in rawhide.