Master with menu controling a contained mashup

Hi guys,

I'd like to make a Master containing a Menu and a Contained Mashup.

What I did:

1 Create 4 Mashups with a random content.

2 Create a Menu

2.1 Add 4 menuitems (Type: Mashup; Link: Mashup_foo; Target: replace page)

3 Create a Master

3.1 Add a Menu widget to the left sidebar

3.2 Add the Menu created in step 2 as value for the Menu property of the Menu widget

4 Add the Master created in step 3 as value for the Master property of any Mashup I use

I thought that would be enough to make it work properly but somehow when I view any of the Mashups and use the menu nothing happens. What am I missing?

Thanks in advance for any help.