Robert,
I can consitantly make you live site give the exclamation point of death, but not a consistant method (or rather, not a consistant number of clicks).
However, if I Turn on the zoning layer, select it from identify and select by rectangle, it will return a selection.
If I start clicking like mad on the results and not quite letting it "finish" drawing after it pans, THEN try to move the mouse up to the top of the widget (like you were going to switch to input mode rather than results) OR hover the mouse over the map somewhere (other than over the identify widget), bam, I get the exclamation point.
Seems to be related to a mouse_over event or something as I can only make it happen when I have the mouse going all over the place while "panning/zooming to" a feature.
R_
Looks like I can do it with the land use layer also, but not as "quickly".
at first, thought it had something to do with the bug on dynamic layers losing (or getting null geometry) once you click off the feature, but, I can make it happen on the land use layer "eventually" also.