>Now I'm getting it to display in the form but it isn't being saved in the actual table! --lincoln

What i'm using now is a default value in the table design for the parent_id:

default value: iif(used("parent_alias", parent_alias.id, "")

so even you issue append blank or insert-sql witout value of parent_id, if the parent table is opened, parent_id wi'll be initialized.

In order to add new items with arrow, what about 'allowaddnew' property ?. This property allos user to add a new record into child table just pressing down arrow key, and if you have the default value as described, it will works fine.
Carlos.