Hi Shoaib, Thanks for the reply. The extents are correct, I've even set it up to display in full world extents. As mentioned before, I've got others layers coming up (eg: shapes, wbmps, geotiffs) in the same mapfile, but this is the only layer that doesn't show up.
I can view the ecw's in ArcGIS, ERViewer, FWTools, etc, except using Mapserver. I guess I forgot to mention that I'm running this on Windows XP, Mapserver 4.8.1 (ms4w download). Hope this helps, please let me know if you need anymore info.
