I've committed a test method to TestCore called "testEmbeddedWithOrder" which demonstrates a failure when using a field of an embedded object in the order by clause.
I've added the auditInfo property to the Item which is of type AuditInfo and uses the AttributeOverride annotation.
Now, when doing
List items = getServer().find(Item.class).order("auditInfo.created asc, type asc").findList();
the generated sql looks like this
select i.customer c0, i.itemNumber c1, i.description c2, i.units c3, i.type c4, i.region c5, i.version c6, i.DATE_MODIFIED c7, i.DATE_CREATED c8, i.MODIFIED_BY c9, i.CREATED_BY c10, i.customer c11, i.type c12, i.customer c13, i.region c14
from item i
order by i.created, i.type
as you can see, the column name in the order by clause for the "created" column is wrong. It should be "i.DATE_CREATED".