DROP DOWN LIST DOES NOT APPEAR USING DATA VALIDATION
 

Good afternoon, this may be a simple question. I have a sheet which uses
validation. The source for validation is just 2 cells which say Yes / No.
Although the validation works in as much as I can only put Yes or No, when I
go to the cell, it does not give me the drop down list. In Data Valiidation,
I am making sure the box, In cell drop down is ticked. The sheet has no
freezed panes. The validation works fine on other pages. I have even tried
to use Edit / Clear All and even after that, the drop down list does not
appear but the valdation does work. Is theer any property for a page which
would stop the drop list appearing??