Equal nest relation uses incorrect SQL and returns incorrect data

The equal nest relation works incorrectly twice. The SQL it produces is wrong. And even if correct the SQL it still returns wrong data.
In my example below $profile->getFriends() returns incorrect data and even tries to write these wrong data when I do $profile->setEmail("..."); $profile->save()
I'm certain that SQL query in Nest.php is wrong, but not only SQL. Even after fixing SQL the data is still incorrect. I digged through the code and suspect that the problem is in Doctrine_Collection which seems to works with only one referenceField, while in an "equal relationship" this field varies row to row.

Here goes steps to reproduce.

Schema.yml
==========

Profile:
columns:
id:
type: integer
primary: true
autoincrement: true
email:
type: varchar(255)
notnull: true
relations:
Friends:

Fixtures:
======

Profile:
-
id: 1
email: one@example.org
-
id: 2
email: two@example.org
-
id: 3
email: three@example.org
-
id: 4
email: four@example.org

UserFriend:
-
requestor_user_id: 1
receiver_user_id: 2
-
requestor_user_id: 4
receiver_user_id: 1
-
requestor_user_id: 2
receiver_user_id: 3

PHP test
=======
$user = Doctrine_Core::getTable('Profile')->find(1);
var_dump($user->getFriends()->toArray());

Output
======
array(2) {
[0]=>
array(3) {
["id"]=>
string(1) "2"
["email"]=>
string(15) "two@example.org"
["UserFriend"]=>
array(2) {
[0]=>
array(3)

[1]=>
array(3)

}
}
[1]=>
array(3) {
["id"]=>
string(1) "4"
["email"]=>
string(16) "four@example.org"
["UserFriend"]=>
array(1) {
[0]=>
array(3)

}
}
}

As it can be seen from output, the relation "UserFriend" shows insane data:

• sometime there are two records in "UserFriend" - and that's wrong
• user 4 has friendship with 4 - that's also wrong, not in the fixtures.