Index: branches/unlabeled/unlabeled-1.4.10/kernel/units/general/helpers/multilanguage.php
===================================================================
diff -u -N -r4360 -r5183
--- branches/unlabeled/unlabeled-1.4.10/kernel/units/general/helpers/multilanguage.php	(.../multilanguage.php)	(revision 4360)
+++ branches/unlabeled/unlabeled-1.4.10/kernel/units/general/helpers/multilanguage.php	(.../multilanguage.php)	(revision 5183)
@@ -179,8 +179,19 @@
 		 */
 		function generateAlterSQL($field_mask, $start_index, $create_count)
 		{
-			$i_count = $start_index + $create_count;
+			static $single_lang = null;
+			if (!isset($single_lang)) {
+				// if single language mode, then create indexes only on primary columns
+				$table_name = $this->Application->getUnitOption('lang', 'TableName');
+				$sql = 'SELECT COUNT(*)
+						FROM '.$table_name.'
+						WHERE Enabled = 1';
+				// if language count = 0, then assume it's multi language mode
+				$single_lang = $this->Conn->GetOne($sql) == 1;
+			}
+			
 			$ret = ' ';
+			$i_count = $start_index + $create_count;
 			while ($start_index < $i_count) {
 				list($prev_field,$type) = explode(' ', sprintf($field_mask, $start_index - 1) );
 				if (substr($prev_field, 0, 3) == 'l0_') {
@@ -198,8 +209,12 @@
 				$field_expression = sprintf($field_mask, $start_index);
 				$ret .= 'ADD COLUMN '.$field_expression.' AFTER `'.$prev_field.'`, ';
 				
+				if ($start_index == $this->Application->GetDefaultLanguageId() || !$single_lang) {
+					// create index for primary language column + for all others (if multiple languages installed)
 				list($field_name, $field_params) = explode(' ', $field_expression, 2); 
 				$ret .= 'ADD INDEX (`'.$field_name.'` (5) ), ';
+				}
+				
 				$start_index++;
 			}
 			return preg_replace('/, $/',';',$ret);