hook_node_access not working I am trying to use hook_node_access to change some permissions when viewing a node type.  The problem is that even when I call it in my module, it doesn't work. 

function MyModule_node_access($node,$op,$account) {
  die("it works!");
}


I can 100% confirm that other hooks in the same module are working fine.  I have disabled and reenabled the module.  I have cleared all cache.  I can confirm that my test user is not uid = 1, and it does not have the "Bypass content access control" permission.  So why is hook_node_access not working for me?  Does it not work by itself?
I used hook_node_access() and had the same issue: It wasn't firing and driving me nuts.

What worked for me was NOT to be logged in as an admin. I went in as a different role and all worked as expected.