Can't have Layout Element based on Tag + Header Element based on another Tag?

Hello,

It looks like I'm not getting the logic of Elements Display Rules or at least it's not working as I expected it.

I have :

- One Layout Element "NoSidebar900px" with just a 900px content and no sidebar + marked as Display Rule = Tag is NoSideBar900px
- One Header Element "LandingPageHeader" with a custom logo + marked as Display Rule = Tag is LandingPageHeader

Now, don't ask me why but if I create a post with the Tags : NoSideBar900px AND LandingPageHeader it will not have the Layout Element with the Header Element as expected.

Any idea why it doesn't work like that?

Hopefully you won't respond with : create a tag NoSideBar900pxLandingPageHeader which would ruin the flexibility ;-)

Thanks,