Index: wp-admin/import/mt.php
===================================================================
--- wp-admin/import/mt.php	(revision 13654)
+++ wp-admin/import/mt.php	(working copy)
@@ -241,7 +241,12 @@
 
 	function save_post(&$post, &$comments, &$pings) {
 		// Reset the counter
-		set_time_limit(30);
+		$max_execution_time = ini_get('max_execution_time');
+		if ( $max_execution_time == '' ) {
+			set_time_limit(30);
+		} else {
+			set_time_limit($max_execution_time);
+		}
 		$post = get_object_vars($post);
 		$post = add_magic_quotes($post);
 		$post = (object) $post;