Kohana ORM Model not loading

In the following code, the "add" action works as expected, but the remove action throws an error citing that Kohana "Cannot delete favorites model because it is not loaded."

Any ideas?

if ($_GET['action'] == 'add')
{
    $favorites = ORM::factory('favorites');
    $favorites->question_id = $_GET['question_id'];
    $favorites->user_id     = Kohana_Facebook::instance()->user_id();
    $favorites->save();
}
elseif ($_GET['action'] == 'remove')
{
$favorites = ORM::factory('favorites')
    ->where('user_id', '=', $facebook->user_id())
    ->and_where('question_id', '=', $_GET['question_id'])
    ->find();
$favorites->delete();
}

A var_dump($favorites) show this:

object(Model_Favorites)#24 (31) { 
["_table_name:protected"]=> string(9) "favorites" 
["_has_one:protected"]=> array(0) { } 
["_belongs_to:protected"]=> array(0) { } 
["_has_many:protected"]=> array(0) { } 
["_load_with:protected"]=> array(0) { } 
["_validation:protected"]=> NULL 
["_object:protected"]=> array(2) { ["user_id"]=> string(8) "60717257" ["question_id"]=> string(1) "2" } 
["_changed:protected"]=> array(0) { } 
["_related:protected"]=> array(0) { } 
["_valid:protected"]=> bool(false) 
["_loaded:protected"]=> bool(false) 
["_saved:protected"]=> bool(false) 
["_sorting:protected"]=> NULL 
["_foreign_key_suffix:protected"]=> string(3) "_id" 
["_object_name:protected"]=> string(9) "favorites" 
["_object_plural:protected"]=> string(11) "favoriteses" 
["_table_columns:protected"]=> array(2) { ["user_id"]=> array(13) { ["type"]=> string(3) "int" ["min"]=> string(11) "-2147483648" ["max"]=> string(10) "2147483647" ["column_name"]=> string(7) "user_id" 
["column_default"]=> NULL 
["data_type"]=> string(3) "int" 
["is_nullable"]=> bool(false) 
["ordinal_position"]=> int(1) 
["display"]=> string(2) "11" 
["comment"]=> string(0) "" 
["extra"]=> string(0) "" 
["key"]=> string(3) "PRI" 
["privileges"]=> string(31) "select,insert,update,references" } 
["question_id"]=> array(13) { ["type"]=> string(3) "int" ["min"]=> string(11) "-2147483648" ["max"]=> string(10) "2147483647" ["column_name"]=> string(11) "question_id" ["column_default"]=> NULL ["data_type"]=> string(3) "int" ["is_nullable"]=> bool(false) ["ordinal_position"]=> int(2) ["display"]=> string(2) "11" ["comment"]=> string(0) "" ["extra"]=> string(0) "" ["key"]=> string(3) "PRI" ["privileges"]=> string(31) "select,insert,update,references" } } ["_updated_column:protected"]=> NULL ["_created_column:protected"]=> NULL ["_primary_key:protected"]=> string(2) "id" ["_primary_key_value:protected"]=> NULL ["_table_names_plural:protected"]=> bool(true) ["_reload_on_wakeup:protected"]=> bool(true) ["_db:protected"]=> object(Database_MySQL)#23 (6) { ["_connection_id:protected"]=> string(40) "f9eb0f07846bef120d6d8414616f81f993f5306a" ["_identifier:protected"]=> string(1) "`" ["last_query"]=> string(98) "SELECT `favorites`.* FROM `favorites` WHERE `user_id` = '60717257' AND `question_id` = '2' LIMIT 1" ["_instance:protected"]=> string(7) "default" ["_connection:protected"]=> resource(73) of type (mysql link) ["_config:protected"]=> array(6) { ["type"]=> string(5) "mysql" ["connection"]=> array(3) { ["hostname"]=> string(9) "localhost" ["database"]=> string(17) "davekiss_dumbpoll" ["persistent"]=> bool(false) } ["table_prefix"]=> string(0) "" ["charset"]=> string(4) "utf8" ["caching"]=> bool(false) ["profiling"]=> bool(true) } } 
["_db_group:protected"]=> NULL 
["_db_applied:protected"]=> array(0) { } 
["_db_pending:protected"]=> array(0) { } 
["_db_reset:protected"]=> bool(true) 
["_db_builder:protected"]=> NULL 
["_with_applied:protected"]=> array(0) { } 
["_cast_data:protected"]=> array(0) { } }

Yes, it is not loaded in your code.

You need to add find() before your delete()

UPD:

As I can see - it is just a relation tables without single PK field (id)

You could delete row with something like:

DB::delete('favorites')->where('user_id', '=', $facebook->user_id())
                       ->and_where('question_id', '=', $_GET['question_id'])
                       ->execute(Database::instance());

Or you could use remove() method (since seems like you're using kohana ORM relations)