I go back up to post #8
Click on karstens_Book1.xls
It opens in excel, shows A2:A19 with the data validation in it, but it is the exact same as the first time when you said it wasn't working.
I can click in any of those cells and type incorrect data.
I tried to restart my computer, thinking it was still opening your first version of the excel document. It is like I am not getting the updated version.