Not sure when or why this happens, but I found this in the Component Showcase logs:

2009-07-22 18:12:59,284 WARN [org.apache.jk.server.JkCoyoteHandler] Unable to send headers
java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
        at org.apache.jk.common.ChannelSocket.send(ChannelSocket.java:509)
        at org.apache.jk.server.JkCoyoteHandler.appendHead(JkCoyoteHandler.java:410)
        at org.apache.jk.server.JkCoyoteHandler.action(JkCoyoteHandler.java:425)
        at org.apache.coyote.Response.action(Response.java:182)
        at org.apache.coyote.Response.sendHeaders(Response.java:374)
        at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:317)
        at org.apache.catalina.connector.OutputBuffer.flush(OutputBuffer.java:293)
        at org.apache.catalina.connector.CoyoteOutputStream.flush(CoyoteOutputStream.java:85)
        at sun.nio.cs.StreamEncoder$CharsetSE.implFlush(StreamEncoder.java:410)
        at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:152)
        at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:213)
        at com.icesoft.faces.webapp.http.common.standard.StreamingContentHandler.respond(StreamingContentHandler.java:25)
        at com.icesoft.faces.webapp.http.servlet.ServletRequestResponse.respondWith(ServletRequestResponse.java:201)
        at com.icesoft.faces.webapp.http.core.UploadServer$2.servlet(UploadServer.java:128)
        at com.icesoft.faces.webapp.http.servlet.ServletRequestResponse.detectEnvironment(ServletRequestResponse.java:262)
        at com.icesoft.faces.webapp.http.core.UploadServer.service(UploadServer.java:63)
        at com.icesoft.faces.webapp.http.common.standard.PathDispatcherServer.service(PathDispatcherServer.java:24)
        at com.icesoft.faces.webapp.http.servlet.BasicAdaptingServlet.service(BasicAdaptingServlet.java:16)
        at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:23)
        at com.icesoft.faces.webapp.http.servlet.SessionDispatcher.service(SessionDispatcher.java:47)
        at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:23)
        at com.icesoft.faces.webapp.http.servlet.MainServlet.service(MainServlet.java:135)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
        at com.icesoft.faces.webapp.xmlhttp.BlockingServlet.service(BlockingServlet.java:56)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
        at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:39)
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:159)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:59)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:307)
        at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:385)
        at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:748)
        at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:678)
        at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:871)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
        at java.lang.Thread.run(Thread.java:595)