MS Excel 2000

Used the function

=INT(RANDBETWEEN(1,5)

to generate a list of random numbers.
Protected the sheet and left the
the range the function is in
locked.

Other parts of the sheet
unlocked.

Why is it that when I enter data
in unlocked cells that the list
of random numbers changes.

I needed to protect my random
generated data from changes
so I copied it as values to
another range and locked that
range so no changes can be
entered.

But I was wondering why the
cells with

=INT(RANDBETWEEN(1,5)

in them change when I am entering
data in other areas of the sheet.

Thanks,

Les