I have just found the answer to my own question, untick the 'Ignore Blanks'
in the validation dialoque box - thanks to the great help at
http://www.contextures.com/tiptech.html Great site, must bookmark it

"pkeegs" wrote:

I am using a validation dropdown box to select from a list in Excel 2003. If
the list is a simple range ($A$1:$A$20) with the error alert checked, I
cannot type a wrong value. However if I have a named range (MyList =
$A$1:$A$20) and I type a wrong value, the error alert will not work and the
cell will accept the error I have typed. Both list and validation dropdowns
are on the same sheet. I have change the list between the simple range and
named range a number of times with the same overall validation settings with
the same result - why is this happening?