Hi Stefan, it sounds like you've got it figured out now?

I think this is controlled in OSX by doing a right-click on the file and then picking the "Open with" menu, if you go to the dialog chooser there you can pick an app for the file type and then there is a checkbox to always open with that app.

I guess that's the UI for Lion and newer, for Snow Leopard right click and choose "Get info" and then the control for which app to use for that file type is on the info pane.

- Michael