This might be hard to debug since it's only happening about 40-50% of the time.
I basically have a rad busy indicator inside a grid.
I'm basically calling a wcf service and putting data into a listbox. When I call the service I set the busy indicator and when I populate the listbox, I set it to isbusy=false. It works, unless I have a silverlight 5 OOB detachable Window open which I open with my app (This is an OOB app). For example it's a help window for the application, nothing to do with that current page.
Half the time it works, but half the time I'll get the text part of the busy indicator "Loading Tasks...." The spinning orb isn't there, just the text area and that part of the grid is shaded out like it's still busy.
When I'm debugging it, that text area only shows up after all the lines of my code are finished. So, it seems like it's out of my control when it shows up.