SO Line Flexfields Update

We need to allow users to update only flexfield values on the sales order line.  They should not be able to change any other fields except the flexfields.  I tried personalization for this and it allows me to change the flexfield values (I disable all other fields) and indicates that changes have been saved but it doesn't actually save the flexfield value changes.  I also looked into using the Open Interface to update the line flexfield values.  I insert values into the oe_lines_iface_all table and run the Order Import request but it doesn't process the record and I don't see