A drawing(DGN) that has a reference containing a raster file is not displaying the raster file.
Ensure sure the reference file is set to display the raster.
At the bottom of the reference dialog there is an icon called "Display Raster Reference'. Ensure that this icon is checked on.
V8i and CONNECT Edition:
Keyin: Raster Display ON
Raster Caching When Image Is Only Displaying The Outline