Index: wp-includes/class-wp-xmlrpc-server.php
===================================================================
--- wp-includes/class-wp-xmlrpc-server.php	(revision 20966)
+++ wp-includes/class-wp-xmlrpc-server.php	(working copy)
@@ -946,7 +946,7 @@
 
 		$post_type = get_post_type_object( $post_data['post_type'] );
 		if ( ! $post_type )
-			return new IXR_Error( 403, __( 'Invalid post type' ) );
+			return new IXR_Error( 403, __( 'Invalid post type.' ) );
 
 		$update = ! empty( $post_data['ID'] );
 
@@ -1072,7 +1072,7 @@
 						$term = get_term_by( 'id', $term_id, $taxonomy );
 
 						if ( ! $term )
-							return new IXR_Error( 403, __( 'Invalid term ID' ) );
+							return new IXR_Error( 403, __( 'Invalid term ID.' ) );
 
 						$terms[$taxonomy][] = (int) $term_id;
 					}
Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 20966)
+++ wp-includes/taxonomy.php	(working copy)
@@ -502,7 +502,7 @@
 
 	foreach ( (array) $taxonomies as $taxonomy ) {
 		if ( ! taxonomy_exists( $taxonomy ) )
-			return new WP_Error( 'invalid_taxonomy', __( 'Invalid Taxonomy' ) );
+			return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
 	}
 
 	$defaults = array( 'order' => 'ASC' );
@@ -855,7 +855,7 @@
 	}
 
 	if ( ! taxonomy_exists($taxonomy) ) {
-		$error = new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));
+		$error = new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 		return $error;
 	}
 
@@ -984,7 +984,7 @@
  */
 function get_term_children( $term_id, $taxonomy ) {
 	if ( ! taxonomy_exists($taxonomy) )
-		return new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));
+		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 
 	$term_id = intval( $term_id );
 
@@ -1174,7 +1174,7 @@
 
 	foreach ( $taxonomies as $taxonomy ) {
 		if ( ! taxonomy_exists($taxonomy) ) {
-			$error = new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));
+			$error = new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 			return $error;
 		}
 	}
@@ -1875,7 +1875,7 @@
 
 	foreach ( (array) $taxonomies as $taxonomy ) {
 		if ( ! taxonomy_exists($taxonomy) )
-			return new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));
+			return new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 	}
 
 	if ( !is_array($object_ids) )
@@ -2015,14 +2015,14 @@
 	global $wpdb;
 
 	if ( ! taxonomy_exists($taxonomy) )
-		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy'));
+		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 
 	$term = apply_filters( 'pre_insert_term', $term, $taxonomy );
 		if ( is_wp_error( $term ) )
 			return $term;
 
 	if ( is_int($term) && 0 == $term )
-		return new WP_Error('invalid_term_id', __('Invalid term ID'));
+		return new WP_Error('invalid_term_id', __('Invalid term ID.'));
 
 	if ( '' == trim($term) )
 		return new WP_Error('empty_term_name', __('A name is required for this term'));
@@ -2146,7 +2146,7 @@
 	$object_id = (int) $object_id;
 
 	if ( ! taxonomy_exists($taxonomy) )
-		return new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));
+		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 
 	if ( !is_array($terms) )
 		$terms = array($terms);
@@ -2320,7 +2320,7 @@
 	global $wpdb;
 
 	if ( ! taxonomy_exists($taxonomy) )
-		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy'));
+		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy.'));
 
 	$term_id = (int) $term_id;