Cross functional Solution Diagrams Change on open

[Kevin]

Created 5 pages of cross functional diagrams using Vsio
2000 SR1. After saving and then re-opening the file 2 of
the pages have hads the diagrams heavily edited.

If Viso file opened READONLY diagrams are ok. How (if
possible) can I recover the diagrams and more importantly
prevent similar occurances and subsequent loss of data

Thanks Kevin