code fails without focus in tab

I'm trying to port a greasemonkey script to a XPI from scratch because
I need to extend functionality beyond what permissions normally can be
granted through GM.  Otherwise I'd use the GM Script compiler and be
happy.

What I have run into is this, unless I am actually on a tab when it
(re)loads, the code doesn't run. If I refresh and maintain focus on
the tab, it runs fine.  No focus, no execute.  Looking for any help I
can get.

Roughly, this is what I am doing, minus the inner code:

gBrowser.addEventListener("DOMContentLoaded", function(aEvent)
{always(aEvent);}, false);

function always(aEvent) {
  if (aEvent.originalTarget instanceof HTMLDocument) {
...
//inner code here does foo
...
  }
}