Did the drop rate of Thavnarian Silk and Leather get nerved or am I just having really bad luck?

last 2 weeks, 15 Dragonskin maps, not one silk or leather, however in those same 2 weeks I have gotten 3 blue Fox Hides, which I hadn't seen at all in 3.0

did they change something or what? anyone else notice this or is it just me?