NPE in Jazz 1.0.1 team server

Hi, I'm getting this exception twice with a second every hour on the hour: Should I be concerned? Thanks.

java.lang.NullPointerException
at net.jazz.ajax.internal.Activator.removedService(Activator.java:81)
at org.osgi.util.tracker.ServiceTracker$Tracked.untrack(ServiceTracker.java:1160)
at org.osgi.util.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:991)
at org.eclipse.osgi.framework.internal.core.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:94)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.dispatchEvent(BundleContextImpl.java:1224)
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:195)
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:141)
at org.eclipse.osgi.framework.internal.core.Framework.publishServiceEventPrivileged(Framework.java:1603)
at org.eclipse.osgi.framework.internal.core.Framework.publishServiceEvent(Framework.java:1578)
at org.eclipse.osgi.framework.internal.core.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:156)
at org.eclipse.equinox.http.servlet.internal.Activator.removeProxyServlet(Activator.java:84)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.destroy(ProxyServlet.java:43)
at org.eclipse.equinox.servletbridge.BridgeServlet.unregisterServletDelegate(BridgeServlet.java:257)
at org.eclipse.equinox.http.servletbridge.internal.Activator.stop(Activator.java:29)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl$3.run(BundleContextImpl.java:1040)
at java.security.AccessController.doPrivileged(AccessController.java:246)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.stop(BundleContextImpl.java:1036)
at org.eclipse.osgi.framework.internal.core.BundleHost.stopWorker(BundleHost.java:457)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.suspend(AbstractBundle.java:526)
at org.eclipse.osgi.framework.internal.core.Framework.suspendBundle(Framework.java:1148)
at org.eclipse.osgi.framework.internal.core.StartLevelManager.decFWSL(StartLevelManager.java:675)
at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:291)
at org.eclipse.osgi.framework.internal.core.StartLevelManager.shutdown(StartLevelManager.java:261)
at org.eclipse.osgi.framework.internal.core.SystemBundle.suspend(SystemBundle.java:188)
at org.eclipse.osgi.framework.internal.core.Framework.shutdown(Framework.java:622)
at org.eclipse.osgi.framework.internal.core.Framework.close(Framework.java:525)
at org.eclipse.osgi.framework.internal.core.OSGi.close(OSGi.java:41)
at org.eclipse.core.runtime.adaptor.EclipseStarter.shutdown(EclipseStarter.java:399)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.equinox.servletbridge.FrameworkLauncher.stop(FrameworkLauncher.java:457)
at org.eclipse.equinox.servletbridge.BridgeServlet.destroy(BridgeServlet.java:70)
at org.apache.catalina.core.StandardWrapper.unload(StandardWrapper.java:1360)
at org.apache.catalina.core.StandardWrapper.stop(StandardWrapper.java:1688)
at org.apache.catalina.core.StandardContext.stop(StandardContext.java:4350)
at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:893)
at org.apache.catalina.startup.HostConfig.undeployApps(HostConfig.java:1180)
at org.apache.catalina.startup.HostConfig.stop(HostConfig.java:1151)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:313)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
at org.apache.catalina.core.ContainerBase.stop(ContainerBase.java:1055)
at org.apache.catalina.core.ContainerBase.stop(ContainerBase.java:1067)
at org.apache.catalina.core.StandardEngine.stop(StandardEngine.java:448)
at org.apache.catalina.core.StandardService.stop(StandardService.java:510)
at org.apache.catalina.core.StandardServer.stop(StandardServer.java:734)
at org.apache.catalina.startup.Catalina.stop(Catalina.java:602)
at org.apache.catalina.startup.Catalina.start(Catalina.java:577)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)