ArcGIS for some time now has issues with how it deals with transparent objects. If particular symbols are currently used and are made transparent, ArcGIS struggles and deal with them when printing but also if trying to export the view to a tiff image. Doing the same process however in Photoshop works. I understand a tiff file contains no transparency but you should be able to embed a transparent symbol/object on to an exisiting raster. In Photoshop I can load a base raster layer and create new transparent layers or symbols and export this back out to a tiff with no issue. If I try this using ArcGIS, ArcGIS appears to get confused and either the printing routine becomes very time consuming or it is impossible to export the current view to a tiff. I believe it is treating the transparent symbol as a transparent band rather than processing the object/symbol seperately and embedding it to the new image. I think with a little bit of research looking at Photoshops ability in this area ESRI should hopefully improve a somewhat frustrating area within ArcGIS. I have managed to do this by exporting the view to a png and then converting back to a tiff but I beleive I should not have to do this.