I am very new to this, so please bear with me, but i have checked the forums, help, etc. but cannot find a solution

I have created a new mainstack, inserted a table field, and connected to a postgresql database. I can see the results fine in the table, I have also added some buttons and text entry fields to allow me to scroll up and down the results from the sql, so far so good.
However, when I an Option Menu and in the Database section, under Save Options, if i select one of these options (currently set to Menu Item Number), whenever i use the Option Menu drop down and select an item I get the error message;
"Update failed on the SQL command: UPDATE dup_header SET
order_action =:1 WHERE unique_ord_id = '3'
Revdb error:
"
I can open the postgres database from within Access and change the field values, so I cannot see it being a permissions problem, but I have to admit I am stumped

Can anyone offer any advice/assistance/help?
EDIT: Not sure if this helps, but if I create a table field and select the "Update cell data after editing", it does not store the changes, if I press Refresh it changes the data back to the original data.
EDIT2: I have just created a small table on the database with only a string field and an integer field, i wrote 2 seperate apps. and neither of them can adjust the fields

Regards
Neil