When you preview or add a single ArcIMS feature class to a map, ArcCatalog and ArcMap do not respect the visible scale range limits set in ArcIMS. The feature class is displayed at its full extent and all features (potentially millions of them) are drawn. The visible scale ranges are respected if the whole feature service is previewed or added.
ArcGIS only recognizes the visible scale range limits for feature classes when the whole feature service is previewed or added to a map.
In ArcGIS 8.1, preview or add whole feature services to retain the visible scale range limits for their constituent feature classes.