I have several files that when they are saved they will not open back up.
when I open a working file it is a "pk /Zip" Compressed file.

EX: 
Please Login or Register  to view this content.
ok that is fine.. it works... but after working and saving several times it saves and it no longer works.. and this is what it shows in txt viewer.

EX: 
Please Login or Register  to view this content.
looks like an old rtf file, but it doesn't open as that either. I have not made any changes in my saving practices. I save the same way each time. It is random. out of 30 files this will happen 5-10 times I have NO ideas how to keep this from happening.