in case of missing rsr files, thumbnailer X may work. it may be necessary to ask mac users about files that don't work in OS X, as the vendors may have no way of testing on a mac. two instances are most common: 1. bad reference file paths (to textures or geometry files) 2. exe files I dunno if vendors are still doing this, but in the old days, it was common to see file paths referring to their C drives.