export to eps

I use DS standard. I loaded a dwg- file and choose to export to an eps- formated file, but this doesn't work. No file is created. Except this I can export the same dwg in a pdf- formated file that is readable with pdf- reader. Otherwise this visible pdf is not loadable in photoshop, while all my other pdf's (text et.c.) could be opened in photoshop. Would be great if someone could help me. M