Because you have the 5 fields listed, there IS not distinct do to the "Blah" table columns that have different city/zip fields... (or at least thats what they appear to be).

In the sample data you showed, it appears to be a 1 to 1 ratio for Dodah and Big for each key "A" column.

However in table "Blah", you have 2 entries for each "A" key... one for Jackson and one for Vicksburg.

What Distinct records to you want... the Dodah/Big with the last entry in the "Blah" table for associate key or what...