RS concurrent delete comment and query hitting the cache

RedScreen on node8 9.0.3
2013-09-18 08:37:40,175 [ajp-apr-8005-exec-15] ERROR OLATRuntimeException - OLAT::ERROR ^% N5-E49 ^% org.olat.core.logging ^%
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_5) AppleWebKit/536.30.1 (KHTML, like Gecko) Version/6.0.5 Safari/536.30.1
*RedScreen* Unable to find org.olat.core.commons.services.commentAndRating.impl.UserCommentImpl with id 331317356
<dispatchinfo>
<componentinfo>
<compname>comments.count</compname>
<compclass>org.olat.core.gui.components.link.Link</compclass>
<extendedinfo>n/a</extendedinfo>
<event>
<class>org.olat.core.gui.control.Event</class>
<command>comments.count</command>
<tostring>com:comments.count,org.olat.core.gui.control.Event@af94d4b4</tostring>
</event>
</componentinfo>
<controllerinfo>
<controllername>org.olat.core.commons.services.commentAndRating.impl.ui.UserCommentsAndRatingsController</controllername>
<controllername>org.olat.modules.webFeed.ui.ItemsController</controllername>
<controllername>org.olat.course.run.RunMainController</controllername>
<controllername>org.olat.core.commons.fullWebApp.BaseFullWebappController</controllername>
<controllername>org.olat.core.commons.chiefcontrollers.controller.simple.SimpleBaseController</controllername>
<controllername>org.olat.core.commons.chiefcontrollers.BaseChiefController</controllername>
</controllerinfo>
</dispatchinfo>
>>> stack of 1.cause::org.olat.core.logging.OLATRuntimeException: Unable to find org.olat.core.commons.services.commentAndRating.impl.UserCommentImpl with id 331317356
-> at org.olat.core.gui.exception.ExceptionWindowController.<init>(ExceptionWindowController.java:107)
at org.olat.core.gui.exception.MsgFactory.createMessageChiefController(MsgFactory.java:57)
at org.olat.core.gui.exception.MsgFactory.createMessageChiefController(MsgFactory.java:46)
at org.olat.core.gui.components.Window.dispatchRequest(Window.java:508)
at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:226)
at org.olat.core.gui.components.Component.dispatchRequest(Component.java:192)
at org.olat.dispatcher.AuthenticatedDispatcher.execute(AuthenticatedDispatcher.java:227)
at org.olat.core.dispatcher.DispatcherAction.execute(DispatcherAction.java:154)
at org.olat.core.servlets.OLATServlet.doPost(OLATServlet.java:155)
at org.olat.core.servlets.OLATServlet.doGet(OLATServlet.java:128)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
>>> stack of 2.cause::javax.persistence.EntityNotFoundException: Unable to find org.olat.core.commons.services.commentAndRating.impl.UserCommentImpl with id 331317356
-> at org.hibernate.ejb.Ejb3Configuration$Ejb3EntityNotFoundDelegate.handleEntityNotFound(Ejb3Configuration.java:157)
at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:212)
at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:246)
at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:150)
at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1092)
at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:1019)
at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:672)
at org.hibernate.type.ManyToOneType.assemble(ManyToOneType.java:280)
at org.hibernate.cache.internal.StandardQueryCache.get(StandardQueryCache.java:161)
at org.hibernate.loader.Loader.getResultFromQueryCache(Loader.java:2453)
at org.hibernate.loader.Loader.listUsingQueryCache(Loader.java:2361)