If the utility acts like it is working but there are no popups coming it could be one of the following reasons:
1. The $headnewmsg variable is not added to the headinclude template. (I even made this mistake in my demo board.

)
2. The board options are not saved in the Admin CP.
3. You added the changes to the /admin/global.php and not to the main global.php or you put the changes in the wrong place.
4. You have Javascript turned off in your browser.
I can't think of any more right now.
This is of course assuming that none of your other hacks change the normal functioning of the $headinclude call in global.php.
Hope this helps.
Scott