I did what you said and it doesn't work.
I opened pyshell, created a sprite called Player, added the platform behavior...
dir (Player) - worked, gave me all the general stuff (no platform stuff)
dir (PlayerPlatform), dir(Player.Platform), dir(Player[Platform]) <- these all just gave me errors
also can't get IsOnGround() to work in my game. tried all the combinations of Player and Platform as I did with pyshell. What am I missing here?