I have several Image Services in my Open Data site, and it seems that just one or two are throwing off the extent shown in the preview map above the search results, even though I have gone through and set the extent for each one in its layer properties in ArcGIS Online. The 2007 image seems like the initial culprit, since its thumbnail is empty, but I think the 2000 image is actually at fault. I have removed this service and replaced it, and the extent is set. It displays normally in ArcMap and ArcGIS Online. I can't find any clues in the REST endpoints, such as having "NaN" set in the extent properties. Has anyone else had this happen?