This is the NPE I get (not sure exactly how to reproduce but it happend after adding, renaming and moving a new MSN user to a group):
java.lang.NullPointerException
at org.jivesoftware.openfire.gateway.protocols.msn.MSNSession.syncContactGroups(MSNSession.java:343)
at org.jivesoftware.openfire.gateway.protocols.msn.MSNSession.updateContact(MSNSession.java:314)
at org.jivesoftware.openfire.gateway.roster.TransportBuddy.setNicknameAndGroups(TransportBuddy.java:280)
at org.jivesoftware.openfire.gateway.BaseTransport.interceptPacket(BaseTransport.java:2353)
at org.jivesoftware.openfire.interceptor.InterceptorManager.invokeInterceptors(InterceptorManager.java:227)
at org.jivesoftware.openfire.IQRouter.route(IQRouter.java:80)
at org.jivesoftware.openfire.spi.PacketRouterImpl.route(PacketRouterImpl.java:67)
at org.jivesoftware.openfire.net.StanzaHandler.processIQ(StanzaHandler.java:303)
at org.jivesoftware.openfire.net.ClientStanzaHandler.processIQ(ClientStanzaHandler.java:78)
at org.jivesoftware.openfire.net.StanzaHandler.process(StanzaHandler.java:268)
at org.jivesoftware.openfire.net.StanzaHandler.process(StanzaHandler.java:167)
at org.jivesoftware.openfire.nio.ConnectionHandler.messageReceived(ConnectionHandler.java:132)
at org.apache.mina.common.support.AbstractIoFilterChain$TailFilter.messageReceived(AbstractIoFilterChain.java:570)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648)
at org.apache.mina.filter.codec.support.SimpleProtocolDecoderOutput.flush(SimpleProtocolDecoderOutput.java:58)
at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:162)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648)
at org.apache.mina.filter.executor.ExecutorFilter.processEvent(ExecutorFilter.java:240)
at org.apache.mina.filter.executor.ExecutorFilter$ProcessEventsRunnable.run(ExecutorFilter.java:284)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
at java.lang.Thread.run(Thread.java:619)