diff --git a/apps/user_ldap/appinfo/app.php b/apps/user_ldap/appinfo/app.php
index 3c6da47d71..0eec7829a4 100644
--- a/apps/user_ldap/appinfo/app.php
+++ b/apps/user_ldap/appinfo/app.php
@@ -40,3 +40,5 @@ $entry = array(
 	'href' => OCP\Util::linkTo( 'user_ldap', 'settings.php' ),
 	'name' => 'LDAP'
 );
+
+OCP\Backgroundjob::addRegularTask('OCA\user_ldap\lib\Jobs', 'updateGroups');
diff --git a/apps/user_ldap/appinfo/database.xml b/apps/user_ldap/appinfo/database.xml
index b228fa2796..3bbd2b09a4 100644
--- a/apps/user_ldap/appinfo/database.xml
+++ b/apps/user_ldap/appinfo/database.xml
@@ -92,4 +92,37 @@
 
  </table>
 
+
+ <table>
+
+  <name>*dbprefix*ldap_group_members</name>
+
+  <declaration>
+
+   <field>
+    <name>owncloudname</name>
+    <type>text</type>
+    <notnull>true</notnull>
+    <length>255</length>
+    <default></default>
+   </field>
+
+   <field>
+    <name>owncloudusers</name>
+    <type>clob</type>
+    <notnull>true</notnull>
+   </field>
+
+   <index>
+    <name>ldap_group_members</name>
+    <unique>true</unique>
+    <field>
+     <name>owncloudname</name>
+    </field>
+   </index>
+
+  </declaration>
+
+ </table>
+
 </database>
\ No newline at end of file
diff --git a/apps/user_ldap/appinfo/version b/apps/user_ldap/appinfo/version
index 5f021e960e..1683a26615 100644
--- a/apps/user_ldap/appinfo/version
+++ b/apps/user_ldap/appinfo/version
@@ -1 +1 @@
-0.2.0.5
\ No newline at end of file
+0.2.0.8
\ No newline at end of file
diff --git a/apps/user_ldap/lib/jobs.php b/apps/user_ldap/lib/jobs.php
new file mode 100644
index 0000000000..76a8e3cbb2
--- /dev/null
+++ b/apps/user_ldap/lib/jobs.php
@@ -0,0 +1,156 @@
+<?php
+
+/**
+ * ownCloud – LDAP Background Jobs
+ *
+ * @author Arthur Schiwon
+ * @copyright 2012 Arthur Schiwon blizzz@owncloud.com
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\user_ldap\lib;
+
+class Jobs {
+
+	//refresh groups every hour
+	static private $refreshInterval = 36;//00;
+
+	static private $groupsFromDB;
+
+	static private $groupBE;
+	static private $connector;
+
+	static public function updateGroups() {
+		\OCP\Util::writeLog('user_ldap', 'Run background job "updateGroups"', \OCP\Util::DEBUG);
+		$lastUpdate = \OCP\Config::getAppValue('user_ldap', 'bgjUpdateGroupsLastRun', 0);
+		if((time() - $lastUpdate) < self::$refreshInterval) {
+			\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – last run too fresh, aborting.', \OCP\Util::DEBUG);
+			//komm runter Werner die Maurer geben ein aus
+			return;
+		}
+
+		$knownGroups = array_keys(self::getKnownGroups());
+		$actualGroups = self::getGroupBE()->getGroups();
+
+		if(empty($actualGroups) && empty($knownGroups)) {
+			\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – groups do not seem to be configured properly, aborting.', \OCP\Util::INFO);
+			\OCP\setAppValue('user_ldap', 'bgjUpdateGroupsLastRun', time());
+			return;
+		}
+
+		self::handleKnownGroups(array_intersect($actualGroups, $knownGroups));
+		self::handleCreatedGroups(array_diff($actualGroups, $knownGroups));
+		self::handleRemovedGroups(array_diff($knownGroups, $actualGroups));
+
+		\OCP\Config::setAppValue('user_ldap', 'bgjUpdateGroupsLastRun', time());
+
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – Finished.', \OCP\Util::DEBUG);
+	}
+
+	static private function handleKnownGroups($groups) {
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – Dealing with known Groups.', \OCP\Util::DEBUG);
+		$query = \OCP\DB::prepare('
+			UPDATE *PREFIX*ldap_group_members
+			SET owncloudusers = ?
+			WHERE owncloudname = ?
+		');
+		foreach($groups as $group) {
+			//we assume, that self::$groupsFromDB has been retrieved already
+		    $knownUsers = unserialize(self::$groupsFromDB[$group]['owncloudusers']);
+		    $actualUsers = self::getGroupBE()->usersInGroup($group);
+		    $hasChanged = false;
+		    foreach(array_diff($knownUsers, $actualUsers) as $removedUser) {
+		        \OCP\Util::emitHook('OC_User', 'post_removeFromGroup', array('uid' => $removedUser, 'gid' => $group));
+		        \OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – "'.$removedUser.'" removed from "'.$group.'".', \OCP\Util::INFO);
+		        $hasChanged = true;
+		    }
+		    foreach(array_diff($actualUsers, $knownUsers) as $addedUser) {
+		        \OCP\Util::emitHook('OC_User', 'post_addFromGroup', array('uid' => $addedUser, 'gid' => $group));
+		        \OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – "'.$addedUser.'" added to "'.$group.'".', \OCP\Util::INFO);
+		        $hasChanged = true;
+		    }
+		    if($hasChanged) {
+				$query->execute(array(serialize($actualUsers), $group));
+		    }
+		}
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – FINISHED dealing with known Groups.', \OCP\Util::DEBUG);
+	}
+
+	static private function handleCreatedGroups($createdGroups) {
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – dealing with created Groups.', \OCP\Util::DEBUG);
+		$query = \OCP\DB::prepare('
+			INSERT
+			INTO *PREFIX*ldap_group_members (owncloudname, owncloudusers)
+			VALUES (?, ?)
+		');
+		foreach($createdGroups as $createdGroup) {
+			\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – new group "'.$createdGroup.'" found.', \OCP\Util::INFO);
+			$users = serialize(self::getGroupBE()->usersInGroup($createdGroup));
+		    $query->execute(array($createdGroup, $users));
+		}
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – FINISHED dealing with created Groups.', \OCP\Util::DEBUG);
+	}
+
+	static private function handleRemovedGroups($removedGroups) {
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – dealing with removed groups.', \OCP\Util::DEBUG);
+		$query = \OCP\DB::prepare('
+			DELETE
+			FROM *PREFIX*ldap_group_members
+			WHERE owncloudname = ?
+		');
+		foreach($removedGroups as $removedGroup) {
+			\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – group "'.$createdGroup.'" was removed.', \OCP\Util::INFO);
+		    $query->execute(array($removedGroup));
+		}
+		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – FINISHED dealing with removed groups.', \OCP\Util::DEBUG);
+	}
+
+	static private function getConnector() {
+		if(!is_null(self::$connector)) {
+			return self::$connector;
+		}
+		self::$connector = new \OCA\user_ldap\lib\Connection('user_ldap');
+		return self::$connector;
+	}
+
+	static private function getGroupBE() {
+		if(!is_null(self::$groupBE)) {
+			return self::$groupBE;
+		}
+		self::getConnector();
+		self::$groupBE = new \OCA\user_ldap\GROUP_LDAP();
+		self::$groupBE->setConnector(self::$connector);
+
+		return self::$groupBE;
+	}
+
+	static private function getKnownGroups() {
+		if(is_array(self::$groupsFromDB)) {
+			return self::$groupsFromDB;
+		}
+		$query = \OCP\DB::prepare('
+			SELECT owncloudname, owncloudusers
+			FROM *PREFIX*ldap_group_members
+		');
+		$result = $query->execute()->fetchAll();
+		self::$groupsFromDB = array();
+		foreach($result as $dataset) {
+		    self::$groupsFromDB[$dataset['owncloudname']] = $dataset;
+		}
+
+		return self::$groupsFromDB;
+	}
+}
\ No newline at end of file