diff --git a/backends/swiften/main.cpp b/backends/swiften/main.cpp
index 93137352ebd82ebc499a85cb71585e30ab983247..3ccc632e86584f736ef2cc2331f58f129243410b 100644
--- a/backends/swiften/main.cpp
+++ b/backends/swiften/main.cpp
@@ -17,9 +17,11 @@
 #endif
 
 #ifndef __FreeBSD__
+#ifndef __MACH__
 // malloc_trim
 #include "malloc.h"
 #endif
+#endif
 
 // Boost
 #include <boost/algorithm/string.hpp>
@@ -189,9 +191,11 @@ class SwiftenPlugin : public NetworkPlugin {
 
 #ifndef WIN32
 #ifndef __FreeBSD__
+#ifndef __MACH__
 			// force returning of memory chunks allocated by libxml2 to kernel
 			malloc_trim(0);
 #endif
+#endif
 #endif
 		}
 
@@ -220,6 +224,10 @@ class SwiftenPlugin : public NetworkPlugin {
 				return;
 			}
 
+			if (presence->getPayload<Swift::MUCUserPayload>() != NULL || presence->getPayload<Swift::MUCPayload>() != NULL) {
+				return;
+			}
+
 			LOG4CXX_INFO(logger, user << ": " << presence->getFrom().toBare().toString() << " presence changed");
 
 			std::string message = presence->getStatus();
@@ -299,7 +307,6 @@ class SwiftenPlugin : public NetworkPlugin {
 				client->getPresenceOracle()->onPresenceChange.disconnect(boost::bind(&SwiftenPlugin::handleSwiftPresenceChanged, this, user, _1));
 				client->disconnect();
 				m_mucs.erase(user);
-				m_users.erase(user);
 			}
 		}
 
@@ -314,7 +321,7 @@ class SwiftenPlugin : public NetworkPlugin {
 				if (client->getMUCRegistry()->isMUC(legacyName)) {
 					message->setType(Swift::Message::Groupchat);
 					boost::shared_ptr<MUCController> muc = m_mucs[user][legacyName];
-					handleMessage(user, legacyName, msg, muc->getNickname(), xhtml);
+// 					handleMessage(user, legacyName, msg, muc->getNickname(), xhtml);
 				}
 
 				client->sendMessage(message);