The GIS data appears, then when I zoom in or out it will disappear. What is going on?
There are a lot of GIS layers that activates and deactivates depending on the scale of the map. An example of this process is the aerial photography. You will notice that the aerial photography will turn on only when you are zoomed in fairly close and as you zoom out it will turn off automatically. This has been purposefully set up to optimize the viewing of the most popular GIS layers at a given scale.