diff -u b/lib/Drupal/profile2/Profile.php b/lib/Drupal/profile2/Profile.php
--- b/lib/Drupal/profile2/Profile.php
+++ b/lib/Drupal/profile2/Profile.php
@@ -100,6 +100,20 @@
   }
 
   /**
+   * Overwrites EntityInterface::id().
+   */
+  public function id() {
+    return isset($this->pid) ? $this->pid : NULL;
+  }
+
+  /**
+   * Overwrites EntityInterface::bundle().
+   */
+  public function bundle() {
+    return $this->type;
+  }
+
+  /**
    * Returns the full url() for the profile.
    */
   public function url() {
diff -u b/profile2.module b/profile2.module
--- b/profile2.module
+++ b/profile2.module
@@ -5,6 +5,9 @@
  * Support for configurable user profiles.
  */
 
+use Drupal\profile2\Profile;
+use Drupal\profile2\ProfileType;
+
 /**
  * Implements hook_entity_info().
  */
@@ -87,7 +90,7 @@
  * @param Drupal\profile2\Profile $profile
  *   A Profile entity.
  */
-function profile2_profile_uri(Drupal\profile2\Profile $profile) {
+function profile2_profile_uri(Profile $profile) {
   return array(
     'path' => 'admin/structure/profiles',
   );
@@ -99,7 +102,7 @@
  * @param Drupal\profile2\ProfileType $profile_type
  *   A ProfileType entity.
  */
-function profile2_profile_type_uri(Drupal\profile2\ProfileType $profile_type) {
+function profile2_profile_type_uri(ProfileType $profile_type) {
   return array(
     'path' => 'admin/structure/profiles/manage',
   );
@@ -298,12 +301,11 @@
  */
 function profile2_get_types($type_name = NULL) {
   $types = entity_load_multiple('profile2_type', NULL, TRUE);
-  if (!is_null($type_name)) {
-    foreach ($types as $key => $type) {
-      if ($type->get('type') != $type_name) {
-        unset($types[$key]);
-      }
+  foreach ($types as $key => $type) {
+    if (is_null($type_name) || $type->get('type') == $type_name) {
+      $types[$type->get('type')] = $type;
     }
+    unset($types[$key]);
   }
   return isset($type_name) ? reset($types) : $types;
 }
@@ -321,7 +323,7 @@
  * @see profile2_load_multiple()
  */
 function profile2_load($pid, $reset = FALSE) {
-  $profiles = profile2_load_multiple(array($pid), array(), $reset);
+  $profiles = profile2_load_multiple($pid, array(), $reset);
   return reset($profiles);
 }
 
@@ -342,7 +344,13 @@
  * @see profile2_load_by_user()
  */
 function profile2_load_multiple($pids = array(), $conditions = array(), $reset = FALSE) {
-  return entity_load('profile2', $pids, $conditions, $reset);
+  if (empty($conditions)) {
+    // it doesn't make sense to use pids and conditions,
+    // therefore ignore pids if conditions were set
+    return entity_load_multiple_by_properties('profile2', $conditions);
+  }
+
+  return entity_load_multiple('profile2', $pids, $reset);
 }
 
 /**
@@ -487,16 +495,21 @@
  * @see profile2_form_submit_handler
  */
 function profile2_form_user_profile_form_alter(&$form, &$form_state) {
-  if (($type = profile2_get_types($form['#user_category'])) && $type->userCategory) {
-    if (empty($form_state['profiles'])) {
-      $profile = profile2_load_by_user($form['#user'], $form['#user_category']);
-      if (empty($profile)) {
-        $profile = profile2_create(array('type' => $form['#user_category'], 'uid' => $form['#user']->uid));
-      }
-      $form_state['profiles'][$profile->type] = $profile;
+  // #user_category no longer exists, use fieldsets instead
+  foreach (profile2_get_types() as $type_name => $profile_type) {
+    $profile = profile2_load_by_user($form_state['entity'], $type_name);
+    if (empty($profile)) {
+      $profile = profile2_create(array('type' => $type_name, 'uid' => $form_state['entity']->uid));
     }
+    $form_state['profiles'][$profile->type] = $profile;
     profile2_attach_form($form, $form_state);
+    // Wrap each profile form in a fieldset.
+    $form['profile_' . $type_name] += array(
+      '#type' => 'fieldset',
+      '#title' => check_plain($profile_type->getTranslation('label')),
+    );
   }
+  return;
 }
 
 /**
@@ -504,7 +517,9 @@
  */
 function profile2_form_user_register_form_alter(&$form, &$form_state) {
   foreach (profile2_get_types() as $type_name => $profile_type) {
-    if (!empty($profile_type->data['registration'])) {
+    $data = $profile_type->get('data');
+    $data = unserialize($data);
+    if (!empty($data['registration'])) {
       if (empty($form_state['profiles'][$type_name])) {
         $form_state['profiles'][$type_name] = profile2_create(array('type' => $type_name));
       }
@@ -539,6 +554,7 @@
   foreach ($form_state['profiles'] as $type => $profile) {
     $form['profile_' . $profile->type]['#tree'] = TRUE;
     $form['profile_' . $profile->type]['#parents'] = array('profile_' . $profile->type);
+
     field_attach_form('profile2', $profile, $form['profile_' . $profile->type], $form_state);
 
     if (count(field_info_instances('profile2', $profile->type)) == 0) {
@@ -558,7 +574,7 @@
     }
   }
   $form['#validate'][] = 'profile2_form_validate_handler';
-  $form['#submit'][] = 'profile2_form_submit_handler';
+  $form_state['submit_handlers'][] = 'profile2_form_submit_handler';
 }
 
 /**
@@ -570,11 +586,13 @@
   foreach ($form_state['profiles'] as $type => $profile) {
     if (isset($form_state['values']['profile_' . $profile->type])) {
       // @see entity_form_field_validate()
-      $pseudo_entity = (object) $form_state['values']['profile_' . $profile->type];
-      $pseudo_entity->type = $type;
+      $pseudo_entity = new Profile(array_merge($form_state['values']['profile_' . $profile->type], array('type' => $type)));
       field_attach_form_validate('profile2', $pseudo_entity, $form['profile_' . $profile->type], $form_state);
     }
   }
+
+  // @todo Looking for a better solution; this one looks like a ugly hack
+  $form_state['submit_handlers'][] = 'profile2_form_submit_handler';
 }
 
 /**