Merge pull request #2982 from aanbar/migration-fix

Fix #2970
diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php
index b226ee8..9185adf 100644
--- a/system/libraries/Migration.php
+++ b/system/libraries/Migration.php
@@ -186,7 +186,15 @@
 	{
 		// Note: We use strings, so that timestamp versions work on 32-bit systems
 		$current_version = $this->_get_version();
-		$target_version = (string) $target_version;
+
+		if ($this->_migration_type === 'sequential')
+		{
+			$target_version = str_pad($target_version, 3, '0', STR_PAD_LEFT);
+		}
+		else
+		{
+			$target_version = (string) $target_version;
+		}
 
 		$migrations = $this->find_migrations();