I installed the Shark007 codecs (incl. 64 bit addon) and they work great in general.
WMC (on Windows 7 x64) now plays everything (mkv, flv, etc), but I can't get it to use FFD.
When I use WMP (x64) to play the same files.FFD and Haali do show up in the tray and work flawlessly
I tried a couple of settings, but didn't manage to get it running.