diff --git a/calendar/inc/class.calendar_groupdav.inc.php b/calendar/inc/class.calendar_groupdav.inc.php
index 00db6f0bce..e3234e694d 100644
--- a/calendar/inc/class.calendar_groupdav.inc.php
+++ b/calendar/inc/class.calendar_groupdav.inc.php
@@ -128,6 +128,7 @@ class calendar_groupdav extends groupdav_handler
 	            			'text/calendar; charset=utf-8; component=VEVENT' : 'text/calendar'),
 					// getlastmodified and getcontentlength are required by WebDAV and Cadaver eg. reports 404 Not found if not set
 					HTTP_WebDAV_Server::mkprop('getlastmodified', $event['modified']),
+					HTTP_WebDAV_Server::mkprop('resourcetype',''),	// iPhone requires that attribute!
 				);
 				//error_log(__FILE__ . __METHOD__ . "Calendar Data : $calendar_data");
 				if ($calendar_data)
@@ -175,7 +176,7 @@ class calendar_groupdav extends groupdav_handler
 				{
 					case 'comp-filter':
 						if ($this->debug > 1) error_log(__METHOD__."($path,...) comp-filter='{$filter['attrs']['name']}'");
-						
+
 						switch($filter['attrs']['name'])
 						{
 							case 'VTODO':
@@ -253,7 +254,7 @@ class calendar_groupdav extends groupdav_handler
 					if ($option['name'] == 'href')
 					{
 						$parts = explode('/',$option['data']);
-		
+
 						if (is_numeric($id = basename(array_pop($parts),'.ics'))) $ids[] = $id;
 					}
 				}
@@ -262,7 +263,7 @@ class calendar_groupdav extends groupdav_handler
 			{
 				$cal_filters['query'][] = 'egw_cal.cal_id IN ('.implode(',',array_map(create_function('$n','return (int)$n;'),$ids)).')';
 			}
-			
+
 			if ($this->debug > 1) error_log(__FILE__ . __METHOD__ ."($path,,,$user,$id) calendar-multiget: ids=".implode(',',$ids));
 		}
 		return true;
@@ -302,10 +303,10 @@ class calendar_groupdav extends groupdav_handler
 		if($this->debug) error_log(__METHOD__."($id, $user)".print_r($options,true));
 		$return_no_access=true;	// as handled by importVCal anyway and allows it to set the status for participants
 		$event = $this->_common_get_put_delete('PUT',$options,$id,$return_no_access);
-		
+
 		if (!is_null($event) && !is_array($event))
 		{
-		
+
 		if($this->debug) error_log(__METHOD__.print_r($event,true).function_backtrace());
 			return $event;
 		}
@@ -362,7 +363,7 @@ class calendar_groupdav extends groupdav_handler
 	function read($id)
 	{
 		//$cal_read = $this->bo->read($id,null,false,'server');//njv: do we actually get anything
-		if ($this->debug > 1) error_log("bo-ical read  :$id:");//njv: 
+		if ($this->debug > 1) error_log("bo-ical read  :$id:");//njv:
 		return $this->bo->read($id,null,false,'server');
 	}
 
@@ -414,6 +415,11 @@ class calendar_groupdav extends groupdav_handler
 		$props[] =	HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-home-set',$_SERVER['SCRIPT_NAME'].'/');
 		// email of the current user, see caldav-sheduling draft
 		$props[] =	HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-user-address-set','MAILTO:'.$GLOBALS['egw_info']['user']['email']);
+		// supported components, currently only VEVENT
+		$props[] =	$sc = HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'supported-calendar-component-set',array(
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'comp',array('name' => 'VEVENT')),
+//			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'comp',array('name' => 'VTODO')),	// not yet supported
+		));
 
 		return $props;
 	}
diff --git a/egw-pear/HTTP/WebDAV/Server.php b/egw-pear/HTTP/WebDAV/Server.php
index 5027f2280a..9dff7350a7 100644
--- a/egw-pear/HTTP/WebDAV/Server.php
+++ b/egw-pear/HTTP/WebDAV/Server.php
@@ -791,6 +791,49 @@ class HTTP_WebDAV_Server
                             break;
                         }
                     } else {
+                        // allow multiple values and attributes, required eg. for caldav:supported-calendar-component-set
+                        if ($prop['ns'] && is_array($prop['val'])) {
+                    		if (!isset($ns_hash[$prop['ns']])) {
+                                $ns_name = "ns".(count($ns_hash) + 1);
+                                $ns_hash[$prop['ns']] = $ns_name;
+                    		}
+                  			$vals = $extra_ns = '';
+                    		foreach($prop['val'] as $subprop)
+                    		{
+		                            if ($subprop['ns'] && $subprop['ns'] != 'DAV:') {
+									// register property namespace if not known yet
+                            		if (!isset($ns_hash[$subprop['ns']])) {
+		                                $ns_name = "ns".(count($ns_hash) + 1);
+		                                $ns_hash[$subprop['ns']] = $ns_name;
+                            		} else {
+                            			$ns_name = $ns_hash[$subprop['ns']];
+                            		}
+	                            	if (strchr($extra_ns,$extra=' xmlns:'.$ns_name.'="'.$subprop['ns'].'"') === false) {
+		                                $extra_ns .= $extra;
+	                            	}
+	                            	$ns_name .= ':';
+	                            } elseif ($subprop['ns'] == 'DAV:') {
+	                            	$ns_name = 'D:';
+	                            } else {
+	                            	$ns_name = '';
+	                            }
+	                            $vals .= "<$ns_name$subprop[name]";
+	                            if (is_array($subprop['val']))	// val contains only attributes, no value
+	                            {
+	                            	foreach($subprop['val'] as $attr => $val)
+	                            	{
+	                            		$vals .= ' '.$attr.'="'.htmlspecialchars($val).'"';
+	                            	}
+	                            	$vals .= '/>';
+	                            }
+	                            else
+	                            {
+	                            	$vals .= '>'.htmlspecialchars($subprop['val'])."</$ns_name$subprop[name]>";
+	                            }
+                   		    }
+                    		echo "     <".$ns_hash[$prop['ns']].":$prop[name]$extra_ns>$vals</".$ns_hash[$prop['ns']].":$prop[name]>\n";
+                        }
+                        else
                         // properties from namespaces != "DAV:" or without any namespace
                         if ($prop["ns"]) {
                             echo "     <" . $ns_hash[$prop["ns"]] . ":$prop[name]>"