Setting up second blog feed

Hi,

I have some problems trying to set up a second menu, with a different kind of blog feed.
For example, we have :

Menu X and item link X  >  Page named X with Slug(url) X which has Parent-None, Template-Blog >Sub page named A with Slug(url) A which has Parent-X, Template-Blog-post

And I added a new menu :

Menu Y and item link Y  >  Page named Y with Slug(url) Y which has Parent-None, Template-Blog >Sub page named B with Slug(url) B which has Parent-Y, Template-Blog-post

Now, the problem is that this menu keep showing the ''Sub page named A with Slug(url) A which has Parent-X'' without displaying only ''Sub page named B with Slug(url) B which has Parent-Y''

Is there something I'm doing wrong ??