See my other comment - his problem seems to not be with the cell with the
formula in it, but rather with unlocked cells that are referenced by the
formula in the Locked cell.

Angus: I don't know of a way to stop that behavior. While the situations I
described there will generally protect against total destruction of a formula
except by a determined end user, there is still the possibility that a
precendent cell could get dragged and dropped into another unlocked cell that
is not referenced anywhere else. Example of one might be where you have an
unlocked cell for user to enter their name or a street address or similar
information.

"kfogle" wrote:

The first thing I would check is this. Make sure that the cells you
want to protect are formatted at "Locked". Protection only works on
Locked cells.

(Select Cell) Format Menu Cells Protection