Dear Tsantee, so much appreciate the feedback. I am actually still struggling, not sure why...but may be you help more. I think the problem is still there and it can be stated this way.
I have created earlier a project and saved it as <.toast> file. I recall trying to save it as <.disk> but, unfortunately, this option did not work for me, i.e. the size of the saved file was only 30KB and it was just icon and nothing else included. So, the only saving option that worked was <.toast> file option at a time. However, when I wanted to open and edit saved <.toast> file, I had to use "copy" window in Toast and drag and drop the <.toast> file into icon. Then I clicked "mount disk" on the screen and created another file (looking like a disk) that I dragged and dropped into "movie" window option in Toast. That allowed me to open the file. After I opened the file, i have noticed that my clips names have been changed and the title of the disk was changed as well, though all my clips were there. I've changed/edited back the clip names and included old title and then tried to save it both ways, i.e. Save as (file menu) and Save as disk image. Again, "Save as" did not work, i.e. nothing was saved, but disk image did work though it started to multiplex, write, etc., so it took time to redo the whole disk rather than to change clips names only. When I finally opened the new generated <.toast> file using exactly the same method as above, I was again surprised to see that the names of the clips and the disk title are wrong, i.e. the new editing that I have applied did not work for saved disk image. So, what is going wrong?