Everywhere I looked, it told me to hook on to the “admin_menu” event when I wanted to queue up my meta box using add_meta_box().  After a bit of messing around, it seemed as though I had it working for the edit post page, but then it wasn’t showing up on the add new post page.  I did a bit of debugging and ensured that it was the fact that the add_meta_box() call wasn’t being queued properly – I assume it had something to do with when it was being added to the meta box queue… ultimately meaning that the “admin_menu” event was too early of an event for me to hook on to.

Nowhere in any of the documentation could I find any information stating what event should be hooked – in fact the documentation relating to add_meta_box() even said to use “admin_menu”.  After a few hours of messing around with their documentation and trying various event hooks, I finally found an event hook that appears to work for me – “admin_head”.  Using that event hook seems to be late enough that my meta box gets queued properly and shows up on both pages, but early enough that it’s not too late to add a meta box to the queue (which was another problem as well).

A friendly note to the WordPress developers – learn to bloody program; use output buffering (though you probably are already) and make useful event hooks.  If you’re going to introduce output queues for things like meta boxes – don’t make using the queues such a hassle (aka, these queues should not be dependant on HTML output)!