In the insert page for the blog items this is the list of fields you are inserting into:
In here I do not see either of your foreign keys listed for the userID or the blogID. According to your earlier posts you should have these two fields also:
BlogItemsBlgID FK (BlogID PK)
BlogItemsVisitorsID FK (VisitorsID PK)
You will need to ensure that you have these columns specified in your insert server behavior. For the values of these fields you should be using the session user id and your recordset value for the blog id like this:
BlogItemsBlgID FK = $row_rsBlogs['BlogID']
BlogItemsVisitorsID FK = $_SESSION['VisitorID']
Give this a try and update the insert server behavior to insert these values into the columns. If your table structure has changed or is different from what is listed here let me know about the differences and I can help you get things adjusted.