category, product listing and product detail

[alain.roger]

Hi,

i'm a little bit lost with VM2.
i have a module that display main products categories. when user clicks on a category, VM product listing of the selected category should display on main content div, the products listing....this works, however, all modules on the left, right and in the main content are not anymore displayed....
what should i do to make a particular module always displayed when user is using VM (category listing, products listing or cart) ?
thx