diff --git a/org.adempiere.base/src/org/compiere/util/DB.java b/org.adempiere.base/src/org/compiere/util/DB.java
index 5ea1e72ae8..bed4ba5b29 100644
--- a/org.adempiere.base/src/org/compiere/util/DB.java
+++ b/org.adempiere.base/src/org/compiere/util/DB.java
@@ -2399,8 +2399,10 @@ public final class DB
 	private static void verifyTrx(String trxName, String sql) {
 		if (trxName != null && Trx.get(trxName, false) == null) {
 			// Using a trx that was previously closed or never opened
-			// this is equivalent to commit without trx (autocommit)
-			log.severe("Transaction closed or never opened ("+trxName+") => this is equivalent to commit without trx (autocommit) --> " + sql); // severe?
+			// probably timed out - throw Exception (IDEMPIERE-644)
+			String msg = "Transaction closed or never opened ("+trxName+") => (maybe timed out)";
+			log.severe(msg); // severe
+			throw new DBException(msg);
 		}
 	}
 
diff --git a/org.adempiere.base/src/org/compiere/util/Trx.java b/org.adempiere.base/src/org/compiere/util/Trx.java
index aa6cb8e03c..3d83006b43 100644
--- a/org.adempiere.base/src/org/compiere/util/Trx.java
+++ b/org.adempiere.base/src/org/compiere/util/Trx.java
@@ -405,6 +405,36 @@ public class Trx
 	}
 	
 
+	/**
+	 * 	Rollback and End Transaction, Close Connection and Throws an Exception
+	 *	@return true if success
+	 */
+	public synchronized boolean rollbackAndCloseOnTimeout() {
+		s_cache.remove(getTrxName());
+
+		//local
+		if (m_connection == null)
+			return true;
+
+		if (isActive())
+			rollback();
+
+		//	Close Connection
+		try
+		{
+			m_connection.close();
+			m_connection = null;
+			m_active = false;
+			fireAfterCloseEvent();
+		}
+		catch (SQLException e)
+		{
+			log.log(Level.SEVERE, m_trxName, e);
+		}
+		log.config(m_trxName);
+		return true;
+	}
+
 	/**
 	 * 	End Transaction and Close Connection
 	 *	@return true if success
@@ -651,7 +681,7 @@ public class Trx
 					if (since > trxs[i].getTimeout() * 1000)
 					{
 						trxs[i].log.log(Level.WARNING, "Transaction timeout. Name="+trxs[i].getTrxName() + ", timeout(sec)="+(since / 1000));
-						trxs[i].close();
+						trxs[i].rollbackAndCloseOnTimeout();
 					}
 				}
 			}