diff --git a/org.adempiere.base/src/org/compiere/model/GridTab.java b/org.adempiere.base/src/org/compiere/model/GridTab.java
index 610015248f..c0d28b9e3b 100644
--- a/org.adempiere.base/src/org/compiere/model/GridTab.java
+++ b/org.adempiere.base/src/org/compiere/model/GridTab.java
@@ -3187,13 +3187,13 @@ public class GridTab implements DataStatusListener, Evaluatee, Serializable
 		int parentLevel = currentLevel-1;
 		if (parentLevel < 0)
 			return tabNo;
-			while (parentLevel != currentLevel)
-			{
-				tabNo--;
-				currentLevel = Env.getContextAsInt(m_vo.ctx, m_vo.WindowNo, tabNo, GridTab.CTX_TabLevel);
-				if (tabNo == 0)
-					break;
-			}
+		while (parentLevel != currentLevel)
+		{
+			tabNo--;
+			currentLevel = Env.getContextAsInt(m_vo.ctx, m_vo.WindowNo, tabNo, GridTab.CTX_TabLevel);
+			if (tabNo == 0)
+				break;
+		}
 		return tabNo;
 	}
 
diff --git a/org.adempiere.base/src/org/compiere/model/GridWindow.java b/org.adempiere.base/src/org/compiere/model/GridWindow.java
index 3eabbc77f3..af60c55880 100644
--- a/org.adempiere.base/src/org/compiere/model/GridWindow.java
+++ b/org.adempiere.base/src/org/compiere/model/GridWindow.java
@@ -166,6 +166,7 @@ public class GridWindow implements Serializable
 			if (mTabVO != null)
 			{
 				GridTab mTab = new GridTab(mTabVO, this, m_virtual);
+				Env.setContext(m_vo.ctx, m_vo.WindowNo, t, GridTab.CTX_TabLevel, Integer.toString(mTab.getTabLevel()));
 				m_tabs.add(mTab);
 			}
 		}	//  for all tabs
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java
index 0566bb62fd..91d671edc1 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessModalDialog.java
@@ -417,6 +417,8 @@ public class ProcessModalDialog extends Window implements EventListener<Event>,
 	}
 
 	private void onOK() {
+		if (!parameterPanel.validateParameters())
+			return;
 		this.startProcess();
 	}
 
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/info/InfoProductWindow.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/info/InfoProductWindow.java
index f941aaea36..fd601e89d6 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/info/InfoProductWindow.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/info/InfoProductWindow.java
@@ -71,7 +71,7 @@ public class InfoProductWindow extends InfoWindow {
     private Textbox fieldDescription;
     
     /** ASI							*/
-	private int	m_M_AttributeSetInstance_ID;
+    protected int	m_M_AttributeSetInstance_ID;
 
 	private Borderlayout contentBorderLayout;
 	
@@ -121,6 +121,24 @@ public class InfoProductWindow extends InfoWindow {
 			}
 			where.append("p.IsSummary='N' ");
 		}
+		
+		for(WEditor editor : editors) {
+			if (editor.getGridField() != null && editor.getGridField().getColumnName().equals("C_BPartner_ID")) {
+				Number value = (Number) editor.getValue();
+				if (value == null || value.intValue() == 0)
+				{
+					if (where.length() > 0) {
+						where.append(" AND ");
+					}
+					
+					where.append("CASE WHEN ppo.m_product_id > 0 THEN ppo.C_BPartner_ID IN (");				
+					where.append("SELECT MAX(ppo.C_BPartner_ID) FROM M_Product_PO ppo ");	
+					where.append("WHERE p.M_Product_ID=ppo.M_Product_ID AND ppo.IsCurrentVendor='Y' AND ppo.IsActive='Y') ");
+					where.append("ELSE 1 = 1 END ");
+				}
+				break;
+			}
+		}
 		return where.toString();
 	}
 
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/session/SessionContextListener.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/session/SessionContextListener.java
index 920e10f7d5..b329771882 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/session/SessionContextListener.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/session/SessionContextListener.java
@@ -69,8 +69,15 @@ public class SessionContextListener implements ExecutionInit,
      */
     public static void setupExecutionContextFromSession(Execution exec) {
     	Session session = exec.getDesktop().getSession();
-		Properties ctx = (Properties)session.getAttribute(SESSION_CTX);
-		HttpSession httpSession = (HttpSession)session.getNativeSession();
+		Properties ctx = null;
+		//catch potential Session already invalidated exception
+		boolean sessionInvalidated = false;
+		try {
+			ctx = (Properties)session.getAttribute(SESSION_CTX);
+		} catch (IllegalStateException e) {
+			sessionInvalidated = true;
+		}
+		HttpSession httpSession = sessionInvalidated ? null : (HttpSession)session.getNativeSession();
 		//create empty context if there's no valid native session
 		if (httpSession == null)
 		{
@@ -217,14 +224,10 @@ public class SessionContextListener implements ExecutionInit,
 	public void complete(Component comp, Event evt) throws Exception
 	{
 		//in servlet thread
-		try {
-			if (ServerContext.getCurrentInstance().isEmpty() || !isContextValid())
-	    	{
-	    		setupExecutionContextFromSession(Executions.getCurrent());
-	    	}
-		} catch (IllegalStateException e) {
-			//safe to ignore session already invalidated
-		}
+		if (ServerContext.getCurrentInstance().isEmpty() || !isContextValid())
+    	{
+    		setupExecutionContextFromSession(Executions.getCurrent());
+    	}
 	}
 
     /**
@@ -309,7 +312,13 @@ public class SessionContextListener implements ExecutionInit,
 			return false;
 		}
 		
-		Properties sessionCtx = (Properties) session.getAttribute(SESSION_CTX);
+		Properties sessionCtx = null;
+		//catch invalidated session exception
+		try {
+			sessionCtx = (Properties) session.getAttribute(SESSION_CTX);
+		} catch (IllegalStateException e) {
+			return false;
+		}
 		if (sessionCtx != null) 
 		{
 			if (Env.getAD_Client_ID(sessionCtx) != Env.getAD_Client_ID(ctx))
@@ -341,6 +350,8 @@ public class SessionContextListener implements ExecutionInit,
 		if (ServerContext.getCurrentInstance().isEmpty() || !isContextValid())
     	{
 			setupExecutionContextFromSession(Executions.getCurrent());
+			if (Env.getCtx().getProperty(SERVLET_SESSION_ID) == null)
+				return;
     	}
 		int AD_Session_ID = Env.getContextAsInt(Env.getCtx(), "#AD_Session_ID");
 		if (AD_Session_ID > 0) {