Help with MS Access query with Informix tables

I have attached from MS Access to Informix tables. I am able, in datasheet view, to see all data from all the columns. When I check what sql has been sent for this it has all the columns selected. However, when I then choose a specific column to order by (other than primary key), Access changes the sql and only asks for the primary key in the select statement while trying to do an order by with the requested column. This is an invalid sql statement and fails. Anyone ever seen this before or have any suggestions? BTW if my table doesnt have a primary key I can order by any column because Access doesnt change the select portion of the sql. Thanks for any help, Heather