DisplayFusion V3.1.10 (Free+Pro) Windows 7 Ultimate (32bit)
Windows Media Center does not snap to the side or corners of either of my two displays. Even when no video is playing Media Center doesn't snap. I tried with Free DisplayFusion and Pro..
I increased the distance to 30px and still Media Center is same.
All other applications snap, no problem.

I did notice some Posts re: MDI applications not snapping on XP with older versions of Displayfusion. In light of that and considering this is happening with v3.1.10 and on Win 7 I just thought I would post so you were aware.
This Win 7 PC is a pretty clean install, still very new.
Display Fusion is a nice app all round. To be honest I like to support independent hackers and this is good stuff! Nice One.