Run-time error '1004' protecting a worksheet

[Emlou85 via OfficeKB.com]

I have some data in some worksheets. On each worksheet I have some cells
that I want the user to be able to select. So I have unlocked these cells.
I have then gone to 'Tools' 'Protection' 'Protect Worksheet' If I don't
enter a password then it works fine. However, if I enter a password then as
soon as I click anywhere on the Worksheet I get an error message:

Run-time error '1004':

The cell or chart you are trying to change is protected and therefore Read-
only.

To modify a protected cell or chart...

Ideally I would prefer to have a password, so any help would be appreciated!
Thank you
Emma

 

[Emlou85 via OfficeKB.com]

Now I get the error message even if I protect the sheet and don't enter a
password!