If I import layers into GeoSrver, they display in GeoExplorer, and I can use the identify tool to find more info about areas of the layer I select. However the table from which this data comes from does not show at the bottom of the screen, as it does for existing example layers. I assume there is a setting somewhere to enable this?
I assume you are using the latest opengeo geoexplorer release, which has a built-in query panel. The fact that you are able to use identify & sld styling indicates that the layer is queryable. What kind of layer is this? Postgis, shapefile? Is it in the same store as the demo data? Are you able to catch any exceptions using firebug?
Also, check if the correct Namespace URI is used in the wfs requests.