Yes this is the Hello_World tutorial in the Developer Portal. It was run on the hosted Foundation Server. The tutorial is loaded from Hello_World_Entities.twx. In the section Introducing Mashup Builder, the user is directed in the Explore the Mashup sub-section to click on various canvas elements to see the effect on the propert and other windows. The initial screen shows all the elements (things) on the canvas. Note that the blue Increment_Count_Property_Button is visible in the lower left-side corner of the canvas. After clicking on the Count_Property_Gauge you will notice that the Gauge now partially obscures the button and the Z-index of the gauge is now 10 (front). This will happen with any object selected including the divider-13 wiidget (blue background). The property box indicate the z-index is "1" but if you click the orange reset button which pops up on the property Z-index line will always shows the z value of '10' in the stack up. Of course you can always rewrite the z-order in the property but I'm sure that this is a bug. The z-index should not be changed by merely clicking on the object. Has this been addressed on the current release?