This is the specification. In order to improve performance in very large files, wrapping mode is fixed to “No-Wrap” mode in case of very large files. You can change the threshold in the file size in the Advanced tab of the Customize dialog box. The default is 100MB. You can change this value to 200MB if you don’t have problem with opening larger files.
OK, I see. Is it anywhere in the Help? I couldn’t find it… :( If no, I think it is worth describing the full list of the functions that do not work with large files.