suddenly dialog shows only black page

suddenly dialog shows only black page

Suddenly all my dialogs are not showing. The background is turning black but the dialog is not showing.  When I click the back link in the browser, the URL changes but the page does not.  I used the web inspector to make sure the markup was being rendered and it seems it has.  This change is happening for all my dialogs and I have not changed them. I have now stripped out all by the most essential js code and it did not change anything.   I just don't see anything wrong and I am not sure where to go from here. 

Thanks. 

UPDATE.  I am using jqm 1.2.