I recently modified a friend's spreadsheet to make it more functional. As
usual, it was a "learn as you go" process.

I learned about the validation and lookup functions this time.

No problem with validation - I created a nice little drop down menu with 32
possible selections. Whatever is selected in this dropdown menu needs to
reference two other cells in a table. The two formulas I used a

=lookup(c7,aa51:aa82,ab51:ab82)
=lookup(c7,aa51:aa82,ac51:ac52)

The problem I am having is that for 31 out of 32 choices it works perfectly.
For one and only one choice it doesn't work. For the 29th choice in the
table, aa79 it references ab80 and ac80.

Why would this function work correctly for 31 out of 32 possibilities?
Email me and I'll send a copy of the sheet.

Thanks.

Dwayne