Cannot move block Main Page Content to different region Realy need your help. I'm working with quite old Drupal 7 site and for some reason I cannot move the Main Page Content block to any different region. When I drag&amp;drop it to the Header region (on block management page) and then click save, looks like it sucessfully moved, but when I go to the actual page I can see that it still located in the Content region. 

Looks like something is preventing Main Page Content block from moving to different region but I don't know exactly what. I've updated Drupal to the latest release - no difference. I've switched to another theme - no luck.

What might be the problem? I'd be very gratefull for any idea.
Something similar happened to me.  The problem was that the main content block was configured to show on "all pages except those listed" and the one listed was front.  When I removed front, I was able to move the block, or rather my changes showed up on the front page too.