I updated utility for getting keycodes, so please try anain.
Just run it (after dowload or fetching+compilation), press media keys and write codes there.
I hope this will help us with addon, 'cause without right keycodes for your KBs I was unable to make it working.
https://bitbucket.org/ArmanHayots/mediakeyshandler/ - hg repo
https://bitbucket.org/ArmanHayots/mediakeyshandler/downloads/GetPressedKeyCodeUtility.zip - binary