I've posted an issue to the menu_views issue queue, but I believe the incompatibility issue is with the megamenu module, as I stated in that issue.
Content of issue posted @ http://drupal.org/node/1926546 :
I've gone through the issues in the queue [for menu_views], and it happens that I'm also using menu_attributes http://drupal.org/project/menu_attributes (7.x-1.0-rc2), special_menu_items http://drupal.org/project/special_menu_items (7.x-2.0+0-dev), and Megamenu http://drupal.org/project/megamenu (7.x-1.x-dev) with menu_views. As per the other issues, I disabled all but megamenu, and the view still wasn't loading.
The following is a screenshot of the menu structure for what Megamenu is using for output: http://d.pr/i/QfHe . In the screenshot, you'll notice that the view block display is being output below the menu; i was making sure it wasn't an access issue with permissions. I also notated the markup where the view should be output.
This screenshot shows the megamenu output above the core menu block for the same menu that megamenu is using, except the view is being output. http://d.pr/i/q6Mr
Comments
Comment #1
markhalliwellPosting my response from the Menu Views issue: