Uneditable query (1 Viewer)

Hello,

i am having a problem with a query i built based on three tables.
I have found the reason why my query is uneditable but dont know how to correct this so i can edit one field in particular.

the query is built on these tables:

tblSalesOrders - primary key is 'So'
tblClients - primary key is 'Acct'
tbl SalesOrderDetails - dual primary key - 'Id' & 'So'

if i remove the dual primary key table, my query is editable.
Does this dual key make it impossible to edit a query?

Also i notice when i add the tables to the query, i first add tblSalesOrders
next i add tblClients and when i do, 'Acct' automatically joins up with 'Acct' from tblSalesOrders, however when i add tblSalesOrderDetails, nothing happens because of this dual key i have.

Can someone please direct me toward a resolution.

thanks,
BJF

Why is So a part of the primary key of tbl SalesOrderDetails. If Id is an autonumber then SO isn't needed. Could you post a screen shot of the relationships or better upload the database or a copy with the relevant parts.

thanks sneuberg for the advice,
i changed the primary key to ID (single key) and it fixed everything.
im not sure why i did the dual key initially; i created that table a few years back and not sure my reasoning behind it.
anyway, thanks for responding .
BJF