We went to look up a part number (ARTRUS019) and the original part number was missing and another part number (HYTCON001) had it's description and was listed in Enter Inventory Items twice, but can only click on one.

If you are running EVO and or up to date i have a simple query which you can run in DE-A on the BKICMSTR and MTICMSTR files and it will tell you if there are any duplicates in the those two files. They are two separate query's. They run quick. If there are then you simply use maintain database to fix it. Let me know if you want it and I can paste it here for you.

There are two separate queries. You have to run them separately. Simply copy them then go to System Mgr then DE-A and past it in the window and execute or export. It will tell you if there are any duplicate part numbers in that file. If there are then you will need to use Maintain Database to fix it(aka delete one)
 
select   bkic_prod_code, count(*)
from     bkicmstr
group by bkic_prod_code
having   count(*) > 1
 
Second query
 
select   mtic_prod_code, count(*)
from     mticmstr
group by mtic_prod_code
having   count(*) > 1