After viewing a portlet with Ajax Push enabled, and then waiting for the Liferay session to expire (see attached screenshot), the browser bombards the server (maxing out the CPU) with repeated requests like the following:

127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "POST /user/joe.bloggs/dashboard?_1_WAR_intramailportlet_javax.faces.resource=listen.icepush&p_p_cacheability=cacheLevelPage&p_p_col_count=1&p_p_col_id=column-2&p_p_id=1_WAR_intramailportlet&p_p_lifecycle=2&p_p_mode=view&p_p_state=normal HTTP/1.1" 302 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "GET /c/portal/login?redirect=%2fuser%2fjoe.bloggs%2fdashboard%3f_1_WAR_intramailportlet_javax.faces.resource%3dlisten.icepush%26p_p_cacheability%3dcacheLevelPage%26p_p_col_count%3d1%26p_p_col_id%3dcolumn-2%26p_p_id%3d1_WAR_intramailportlet%26p_p_lifecycle%3d2%26p_p_mode%3dview%26p_p_state%3dnormal&p_l_id=0 HTTP/1.1" 302 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "GET /web/guest/home?p_p_state=maximized&p_p_mode=view&saveLastPath=0&_58_struts_action=%2flogin%2flogin&p_p_id=58&p_p_lifecycle=0&_58_redirect=%2fuser%2fjoe.bloggs%2fdashboard%3f_1_WAR_intramailportlet_javax.faces.resource%3dlisten.icepush%26p_p_cacheability%3dcacheLevelPage%26p_p_col_count%3d1%26p_p_col_id%3dcolumn-2%26p_p_id%3d1_WAR_intramailportlet%26p_p_lifecycle%3d2%26p_p_mode%3dview%26p_p_state%3dnormal HTTP/1.1" 304 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "POST /user/joe.bloggs/dashboard?_1_WAR_intramailportlet_javax.faces.resource=listen.icepush&p_p_cacheability=cacheLevelPage&p_p_col_count=1&p_p_col_id=column-2&p_p_id=1_WAR_intramailportlet&p_p_lifecycle=2&p_p_mode=view&p_p_state=normal HTTP/1.1" 302 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "GET /c/portal/login?redirect=%2fuser%2fjoe.bloggs%2fdashboard%3f_1_WAR_intramailportlet_javax.faces.resource%3dlisten.icepush%26p_p_cacheability%3dcacheLevelPage%26p_p_col_count%3d1%26p_p_col_id%3dcolumn-2%26p_p_id%3d1_WAR_intramailportlet%26p_p_lifecycle%3d2%26p_p_mode%3dview%26p_p_state%3dnormal&p_l_id=0 HTTP/1.1" 302 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "GET /web/guest/home?p_p_state=maximized&p_p_mode=view&saveLastPath=0&_58_struts_action=%2flogin%2flogin&p_p_id=58&p_p_lifecycle=0&_58_redirect=%2fuser%2fjoe.bloggs%2fdashboard%3f_1_WAR_intramailportlet_javax.faces.resource%3dlisten.icepush%26p_p_cacheability%3dcacheLevelPage%26p_p_col_count%3d1%26p_p_col_id%3dcolumn-2%26p_p_id%3d1_WAR_intramailportlet%26p_p_lifecycle%3d2%26p_p_mode%3dview%26p_p_state%3dnormal HTTP/1.1" 304 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "POST /user/joe.bloggs/dashboard?_1_WAR_intramailportlet_javax.faces.resource=listen.icepush&p_p_cacheability=cacheLevelPage&p_p_col_count=1&p_p_col_id=column-2&p_p_id=1_WAR_intramailportlet&p_p_lifecycle=2&p_p_mode=view&p_p_state=normal HTTP/1.1" 302 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "GET /c/portal/login?redirect=%2fuser%2fjoe.bloggs%2fdashboard%3f_1_WAR_intramailportlet_javax.faces.resource%3dlisten.icepush%26p_p_cacheability%3dcacheLevelPage%26p_p_col_count%3d1%26p_p_col_id%3dcolumn-2%26p_p_id%3d1_WAR_intramailportlet%26p_p_lifecycle%3d2%26p_p_mode%3dview%26p_p_state%3dnormal&p_l_id=0 HTTP/1.1" 302 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "GET /web/guest/home?p_p_state=maximized&p_p_mode=view&saveLastPath=0&_58_struts_action=%2flogin%2flogin&p_p_id=58&p_p_lifecycle=0&_58_redirect=%2fuser%2fjoe.bloggs%2fdashboard%3f_1_WAR_intramailportlet_javax.faces.resource%3dlisten.icepush%26p_p_cacheability%3dcacheLevelPage%26p_p_col_count%3d1%26p_p_col_id%3dcolumn-2%26p_p_id%3d1_WAR_intramailportlet%26p_p_lifecycle%3d2%26p_p_mode%3dview%26p_p_state%3dnormal HTTP/1.1" 304 -
127.0.0.1 - - [03/Dec/2010:20:37:38 +0000] "POST /user/joe.bloggs/dashboard?_1_WAR_intramailportlet_javax.faces.resource=listen.icepush&p_p_cacheability=cacheLevelPage&p_p_col_count=1&p_p_col_id=column-2&p_p_id=1_WAR_intramailportlet&p_p_lifecycle=2&p_p_mode=view&p_p_state=normal HTTP/1.1" 302 -