Cannot insert new record into sql 2005 View from Access form

I have a sql server 2005 database containing several tables: Orders,
Shipping, and Planning. They are joined together in the sql view V_Main. I
also have a ms access 2007 mdb that links to V_Main via odbc. I created an
access form using the view V_Main as the record source. I cannot insert a
new record into each of the 3 base tables using V_Main as the record source.
A new record is inserted into only one table.
I did find a suggestion in another forum that suggested copying the sql that
creates the view into the form's record source, rather than the name of the
view. This does work, but adds another place to be updated manually should
and other table be added to the view in the future.
I did verify that all tables have primary keys.
How can I add a new record for each of the 3 base tables using the view as
the record source? What is the code that could be placed in vb of the form?
Any suggestions would be helpful.
Thank you.