Protection & Locked issue

[ah]

Hi;

I would appreciate if someone could help me with the following:

I've a protected excel templates that contain some locked cells as well as
unlocked cells. It works well at my end. But, after i distribute it to the
user, I found that some of the unlocked cell are locked and I'm not be able
to enter anything on it when the user return the template back to me.

I tried to unprotect the sheet, and found that the cell setting has been
changed to "protected". This is something strange as the user does not have
the passsword to unprotect the sheet, and they did not change the file format.

Appreciate if someone could help me with this.
Thanks a lot!

 

[ah]

Is there any way that I can prevent user from changing the "unlocked" cell to
"Locked"?