When I open the Properties of a game in my library, and navigate to Installed Files, then click the Browse... button, it does not work as expected. The celluloid media player activates and freezes up. I need to force kill the celluloid process to close the window.

Can anyone tell me what might make the steam client behave in this way?

Just additional note, there is another forum post here, which says the file browser in the "Add a Game" menu fails to work properly, but that function works okay for me.