Index: continuum-webapp/src/main/java/org/apache/maven/continuum/web/action/ProjectGroupAction.java
===================================================================
--- continuum-webapp/src/main/java/org/apache/maven/continuum/web/action/ProjectGroupAction.java	(revision 781234)
+++ continuum-webapp/src/main/java/org/apache/maven/continuum/web/action/ProjectGroupAction.java	(working copy)
@@ -156,6 +156,11 @@
             addActionError( authzE.getMessage() );
             return REQUIRES_AUTHORIZATION;
         }
+        catch ( ContinuumException e )
+        {
+            addActionError( getText( "projectGroup.invalid.id", "Invalid Project Group Id: " + projectGroupId, new Integer( projectGroupId ).toString() ) );
+            return "to_summary_page";
+        }
 
         projectGroup = getContinuum().getProjectGroupWithProjects( projectGroupId );
 
Index: continuum-webapp/src/main/resources/struts.xml
===================================================================
--- continuum-webapp/src/main/resources/struts.xml	(revision 781234)
+++ continuum-webapp/src/main/resources/struts.xml	(working copy)
@@ -320,8 +320,12 @@
     * project group actions
     -->
     <action name="projectGroupSummary" class="projectGroup" method="summary">
+      <interceptor-ref name="storeStack"/>
       <interceptor-ref name="retrieveStack"/>
       <result name="success">/WEB-INF/jsp/projectGroupSummary.jsp</result>
+      <result name="to_summary_page" type="redirect-action">
+        <param name="actionName">groupSummary</param>
+      </result>
     </action>
 
     <action name="projectGroupMembers" class="projectGroup" method="members">
Index: continuum-webapp/src/main/resources/localization/Continuum.properties
===================================================================
--- continuum-webapp/src/main/resources/localization/Continuum.properties	(revision 781234)
+++ continuum-webapp/src/main/resources/localization/Continuum.properties	(working copy)
@@ -197,6 +197,7 @@
 projectGroup.scmRoot.title = Project Group Scm Root
 projectGroup.scmRoot.label = Scm Root URL
 projectGroup.cancelGroupBuild = Cancel Group Build
+projectGroup.invalid.id = Invalid Project Group Id: {0}
 
 # ----------------------------------------------------------------------
 # Page: Project Group - Members