diff --git a/calendar/inc/class.bocal.inc.php b/calendar/inc/class.bocal.inc.php
index 4c04ba60eb..d8c6db38cd 100644
--- a/calendar/inc/class.bocal.inc.php
+++ b/calendar/inc/class.bocal.inc.php
@@ -246,7 +246,8 @@ class bocal
 	 *  show_rejected if set rejected invitation are shown only when true, otherwise it depends on the cal-pref or a running query
 	 *  ignore_acl if set and true no check_perms for a general EGW_ACL_READ grants is performed
 	 *  enum_groups boolean if set and true, group-members will be added as participants with status 'G'
-	 * @return array of events or array with YYYYMMDD strings / array of events pairs (depending on $daywise param)
+	 * @return array of events or array with YYYYMMDD strings / array of events pairs (depending on $daywise param) 
+	 *	or false if there are no read-grants from _any_ of the requested users
 	 */
 	function &search($params)
 	{
@@ -276,6 +277,9 @@ class bocal
 			{
 				continue;	// for non-groups (eg. users), we stop here if we have no read-rights
 			}
+			// the further code is only for real users
+			if (!is_numeric($user)) continue;
+
 			// for groups we have to include the members
 			if ($GLOBALS['egw']->accounts->get_type($user) == 'g')
 			{
@@ -312,7 +316,7 @@ class bocal
 		// as calling the so-layer without users would give the events of all users (!)
 		if (!count($users))
 		{
-			return array();
+			return false;
 		}
 		if (isset($params['start'])) $start = $this->date2ts($params['start']);
 
@@ -833,6 +837,29 @@ class bocal
 		}
 	}
 
+	/**
+	 * Fetch information about a resource
+	 *
+	 * We do some caching here, as the resource itself might not do it.
+	 *
+	 * @param string $uid string with one-letter resource-type and numerical resource-id, eg. "r19"
+	 * @return array/boolean array with keys res_id,cat_id,name,useable (name definied by max_quantity in $this->resources),rights,responsible or false if $uid is not found
+	 */
+	function resource_info($uid)
+	{
+		static $res_info_cache = array();
+		
+		if (!isset($res_info_cache[$uid]))
+		{
+			list($res_info_cache[$uid]) = $this->resources[$uid{0}]['info'] ? ExecMethod($this->resources[$uid{0}]['info'],substr($uid,1)) : false;
+		}
+		if ($this->debug && ($this->debug > 2 || $this->debug == 'resource_info'))
+		{
+			$this->debug_message('bocal::resource_info(%1) = %2',True,$uid,$res_info_cache[$uid]);
+		}
+		return $res_info_cache[$uid];
+	}
+
 	/**
 	 * Checks if the current user has the necessary ACL rights
 	 *
@@ -852,9 +879,9 @@ class bocal
 		$event_in = $event;
 		if ($other && !is_numeric($other))
 		{
-			$resource = ExecMethod($this->resources[$other{0}]['info'],substr($other,1));
+			$resource = $this->resource_info($other);
 
-			return $needed & $resource[0]['rights'];
+			return $needed & $resource['rights'];
 		}
 		if (is_int($event) && $event == 0)
 		{
@@ -902,8 +929,8 @@ class bocal
 				elseif (!is_numeric($uid))
 				{
 					// if we have a resource as participant
-					$resource = ExecMethod($this->resources[$uid{0}]['info'],substr($uid,1));
-					$grants |= $resource[0]['rights'];
+					$resource = $this->resource_info($uid);
+					$grants |= $resource['rights'];
 				}	
 			}
 		}
@@ -1250,23 +1277,14 @@ class bocal
 	{
 		static $id2lid = array();
 		
+		if ($use_type && $use_type != 'u') $id = $use_type.$id;
+
 		if (!isset($id2lid[$id]))
 		{
-			if (!is_numeric($id) || $use_type && $use_type != 'u')
+			if (!is_numeric($id))
 			{
-				$type = $use_type ? $use_type : $id[0];
-				$res_id = $use_type ? $id : (int) substr($id,1);
-
-				if (isset($this->resources[$type]) && isset($this->resources[$type]['info']))
-				{
-					list($data) = ExecMethod($this->resources[$type]['info'],$res_id);
-					//echo "$type$res_id: "; _debug_array($data);
-					$id2lid[$id] = $data['name'];
-				}
-				else
-				{
-					$id2lid[$id] = "resource($id)";
-				}
+				$res_info = $this->resource_info($id);
+				$id2lid[$id] = $res_info && isset($res_info['name']) ? $res_info['name'] : "resource($id)";
 			}
 			else
 			{
diff --git a/calendar/inc/class.bocalupdate.inc.php b/calendar/inc/class.bocalupdate.inc.php
index 740221747e..031570ca6b 100644
--- a/calendar/inc/class.bocalupdate.inc.php
+++ b/calendar/inc/class.bocalupdate.inc.php
@@ -126,7 +126,7 @@ class bocalupdate extends bocal
 			$types_with_quantity = array();
 			foreach($this->resources as $type => $data)
 			{
-				if ($data['use_quantity']) $types_with_quantity[] = $type;
+				if ($data['max_quantity']) $types_with_quantity[] = $type;
 			}
 			// get all NOT rejected participants and evtl. their quantity
 			$quantity = $users = array();
@@ -135,9 +135,9 @@ class bocalupdate extends bocal
 				if ($status[0] == 'R') continue;	// ignore rejected participants
 
 				$users[] = $uid;
-				if (in_array($uid[0],$types_with_quantity))
+				if (in_array($uid{0},$types_with_quantity))
 				{
-					$quantity[$uid] = min(1,(int) substr($overlap['participants']['uid'],2));
+					$quantity[$uid] = max(1,(int) substr($status,2));
 				}
 			}
 			$overlapping_events =& $this->search(array(
@@ -167,26 +167,25 @@ class bocalupdate extends bocal
 				$common_parts = array_intersect($users,array_keys($overlap['participants']));
 				foreach($common_parts as $n => $uid)
 				{
-					if ($overlap['participants'][$uid][0] == 'R') 
+					if ($overlap['participants'][$uid]{0} == 'R') 
 					{
 						unset($common_parts[$uid]);
 						continue;
 					}
-					if (is_numeric($uid) || !in_array($uid[0],$types_with_quantity))
+					if (is_numeric($uid) || !in_array($uid{0},$types_with_quantity))
 					{
 						continue;	// no quantity check: quantity allways 1 ==> conflict
 					}
 					if (!isset($max_quantity[$uid]))
 					{
-						$res_info = ExecMethod($this->resources[$uid[0]]['info']);
-						$max_quantity[$uid] = $res_info[$this->resources[$uid[0]]['use_quantity']];
+						$res_info = $this->resource_info($uid);
+						$max_quantity[$uid] = $res_info[$this->resources[$uid{0}]['max_quantity']];
 					}
-					$quantity[$uid] += min(1,(int) substr($overlap['participants']['uid'],2));
-					
-					if ($quantity[$uid] <= $max_quantity)
+					$quantity[$uid] += max(1,(int) substr($overlap['participants'][$uid],2));
+					if ($quantity[$uid] <= $max_quantity[$uid])
 					{
 						$possible_quantity_conflicts[$uid][] =& $overlapping_events[$k];	// an other event can give the conflict
-						unset($common_parts[$uid]);
+						unset($common_parts[$n]);
 						continue;
 					}
 					// now we have a quantity conflict for $uid
@@ -205,9 +204,9 @@ class bocalupdate extends bocal
 			{
 				if ($quantity[$uid] > $max)
 				{
-					foreach($possible_quantity_conflicts[$uid] as $conflict)
+					foreach((array)$possible_quantity_conflicts[$uid] as $conflict)
 					{
-						$conflicts[$conflict['id'].'-'.$this->bo->date2ts($conflict['start'])] =& $possible_quantity_conflicts[$k];
+						$conflicts[$conflict['id'].'-'.$this->date2ts($conflict['start'])] =& $possible_quantity_conflicts[$k];
 					}
 				}
 			}
@@ -233,7 +232,7 @@ class bocalupdate extends bocal
 					$this->debug_message('bocalupdate::update() %1 conflicts found %2',false,count($conflicts),$conflicts);
 				}
 				return $conflicts;
-			}						
+			}					
 		}
 		// save the event to the database
 		if ($touch_modified)