I have created a drop down menus using filters referencing the contents of other cells. The users select a category of equipment from a drop-down list in column C and then they get a filtered drop down list in column D based on the category they selected. It works beautifully.

The data validation formula in column C is:

=IF(D3="",Category_List,INDEX(Category_Column,MATCH(D3,Equipment_Column,0)))

The forumula in column D is:

=OFFSET(Category_Start,MATCH(C3,Category_Column,0)-1,8,COUNTIF(Category_Column,C3),1)

The results are:

Drop down Category Equipment Lists.jpg

However, on occassion, the data validation drop-down arrow goes MIA -- usually when I send the file to others, but it has happened to me too. I check the data validation and it's still there, and if I simply paste the formula back into the data validation source, and click OK, it comes back. The file is macro-enabled. I have already told people they need to have macros-enabled and that they need to be using 2007 or 2010. I have found many other people posting they have this problem, and it seems as though saving it as a marco-enabled file is supposed to fix the problem, but mine is already macro-enabled. Any thoughts?

Trish