[jQuery] $.blockUI cannot "find" my div

[jQuery] $.blockUI cannot "find" my div


hmmm
For some reason,
when the following code executes:
$.blockUI({ message: $('#workingContainer'), css: { border: 'solid
2px #01ADEE', width:'470px', left:'50%' } });
blockUI does NOT find/ignores my <div> called workingContainer:
<div id="workingContainer" style="display:none; cursor: default"><img
src="images/shared/busy.gif" /> Retrieving data, just a moment...</
div>
and uses the default text/css... "Please Wait".
So BlockUI is blocking, but won't take my markup in the argument....
any thoughts why this may be? my blockUI is in a seperate ,js file
than the file containing my <div>, but all the other javascript and
HTML between the 2 files works great...
Thanks for any advice!
Dustin