Only in src/: TestQueryWithNullArgument.java
diff -ru old/org/postgresql/jdbc2/AbstractJdbc2Connection.java src/org/postgresql/jdbc2/AbstractJdbc2Connection.java
--- old/org/postgresql/jdbc2/AbstractJdbc2Connection.java	2013-09-10 19:59:31.661212020 +0300
+++ src/org/postgresql/jdbc2/AbstractJdbc2Connection.java	2013-09-10 19:56:39.161203807 +0300
@@ -228,9 +228,15 @@
             bindStringAsVarchar = haveMinimumCompatibleVersion("8.0");
         }
 
+        int timestamp_oid;
+        timestamp_oid = Oid.UNSPECIFIED; // Default
+        if ("with_timezone".equals(info.getProperty("timestamp")))
+            timestamp_oid = Oid.TIMESTAMPTZ;
+        if ("without_timezone".equals(info.getProperty("timestamp")))
+            timestamp_oid = Oid.TIMESTAMP;
         // Initialize timestamp stuff
         timestampUtils = new TimestampUtils(haveMinimumServerVersion("7.4"), haveMinimumServerVersion("8.2"),
-                                            !protoConnection.getIntegerDateTimes());
+                                            !protoConnection.getIntegerDateTimes(), timestamp_oid);
 
         // Initialize common queries.
         commitQuery = getQueryExecutor().createSimpleQuery("COMMIT");
diff -ru old/org/postgresql/jdbc2/AbstractJdbc2Statement.java src/org/postgresql/jdbc2/AbstractJdbc2Statement.java
--- old/org/postgresql/jdbc2/AbstractJdbc2Statement.java	2013-09-10 19:59:44.405212627 +0300
+++ src/org/postgresql/jdbc2/AbstractJdbc2Statement.java	2013-09-10 20:03:43.781224024 +0300
@@ -3315,7 +3315,8 @@
         // we're actually dealing with, UNSPECIFIED seems the lesser evil, even if it
         // does give more scope for type-mismatch errors being silently hidden.
 
-        bindString(i, connection.getTimestampUtils().toString(cal, t), Oid.UNSPECIFIED); // Let the server infer the right type.
+        TimestampUtils utils = connection.getTimestampUtils();
+        bindString(i, utils.toString(cal, t), utils.timestampOid); // Let the server infer the right type.
     }
 
     // ** JDBC 2 Extensions for CallableStatement**
diff -ru old/org/postgresql/jdbc2/TimestampUtils.java src/org/postgresql/jdbc2/TimestampUtils.java
--- old/org/postgresql/jdbc2/TimestampUtils.java	2013-09-10 19:59:11.905211079 +0300
+++ src/org/postgresql/jdbc2/TimestampUtils.java	2013-09-10 20:07:20.785234356 +0300
@@ -47,10 +47,27 @@
      */
     private final boolean usesDouble;
 
+    /**
+     * OID to use for {@link Timestamp} type.<br>
+     * Must be one of:
+     * <ul>
+     * <li>{@link Oid#UNSPECIFIED}</li>
+     * <li>{@link Oid#TIMESTAMP}</li>
+     * <li>{@link Oid#TIMESTAMPTZ}</li>
+     * </ul>
+     * Typically should be set from the JDBC URL or parameters.
+     */
+    public final int timestampOid;
+
     TimestampUtils(boolean min74, boolean min82, boolean usesDouble) {
+        this(min74, min82, usesDouble, Oid.UNSPECIFIED);
+    }
+
+    TimestampUtils(boolean min74, boolean min82, boolean usesDouble, int timestampOid) {
         this.min74 = min74;
         this.min82 = min82;
         this.usesDouble = usesDouble;
+        this.timestampOid = timestampOid;
     }
 
     private Calendar getCalendar(int sign, int hr, int min, int sec) {