[gnome-db] Custom objects.

I'm having a problem populating a custom object.

Given:
---
const gchar *xml_description =
    "<table name=\"" DOCUMENT_TABLE_NAME "\">"
    "  <column name=\"id\" type=\"gint\" pkey=\"TRUE\" autoinc=\"TRUE
\"/>"
    "  <column name=\"element\"/>"
    "  <column name=\"attributes\"/>"
    "  <column name=\"prev\" type=\"gint\" nullok=\"FALSE\"/>"
    "  <column name=\"next\" type=\"gint\" nullok=\"FALSE\"/>"
    "  <unique/>"
    "    <column name=\"attributes\"/>"
    "  <unique/>"
    "</table>";
---
and after added correctly the table, the inserted rows having
_equals_ elements columns are ignored, just like
element would be a part of the key, but I am not
set that in the description AFAIK

What could be my mistake ?

Thanks in advance...