Elizabeth I to, when downloading files and opening, initially save as a .kes in K1000. I cannot give you a good reason except that is the preferred K1000 file type. What I've noticed, however, is that when saving as a .rtf just prior to uploading to BookShare, there are seldom uploading problems. .rtf files continually opened and closed in K1000 seem to have greater chance of not being recognized as .rtf by the BookShare system. Hence, I edit as .kes and only save as a .rtf as a final step. This may be sheer coincidence and nothing more.