Another Dependent Data Validation Combobox

Hi everyone,

I'm still curious about the sample from Contextures, http://www.contextures.com/excelfiles.html (DV0032 - Dependent Data Validation Combobox)

I have made a modification from its file (sample is attached). First drop list can be autocomplete, but the second cannot. For the comparing, I made row 2 in ValidationSample sheet is my modification, and row 3 is the original.

Can you guys help me find the solution? thank you before..