UPDATE query generate ambiguous statement

When creating an UPDATE query, the table names are not aliased like in a SELECT statement. This causes ambiguous column names when JOINING in an UPDATE.

E.g.
$q = $this->createQuery('st')
->update('SomeTable st')
->set('st.position','st.position + 1')
->leftJoin('st.SomeOtherTable sot ON st.some_id = sot.id')
->where('st.id <> ?', $someId)
->andWhere('sot.some_column = ?', $someValue)

The generated SQL for this is :
UPDATE some_table
LEFT JOIN some_other_table sot ON st.some_id = sot.id
SET position = position + 1, updated_at = 2011-04-13 11:01:03, updated_at = 2011-04-13 11:01:03
WHERE (id <> 4 AND some_column = 7)

Clearly here "updated_at" and "id" are ambiguous columns. Why the tables are not automatically aliased with unique aliases like in a SELECT statement, and the aliases written before the column name ?

Thanks.