Handling of translation does not use TYPO3 API
The handling of translated records (when records are added to the sitemap) does not rely on the TYPO3 API for managing translations. It is conceptually wrong to fetch records directly based on sys_language_uid. Instead records should be fetched for languages 0 (default) and -1 (All) and then overlaid with the available translations, using the API provided by t3lib_pageSelect.
Attached patch does this when language handling is not disabled and current language is not default.
This is a pretty serious issue as it leads to the creation of URLs pointing to news items (for example) using the translated record's uid whereas any well-programmed TYPO3 extension expects to receive the uid in the original language and then overlay it with its translation.