[TYPO3-english] Question: Language link / menu links

[isabella.holz at online.de]

Hi all,
a friend recommended this list for two special typo3 problems:
1. The menu links of www.intelligenceday.com http://www.intelligenceday.com  sometimes (in my experience rather seldom) link to the page IDs, which do not work then. when you take a look at www.tagderintelligenz.de http://www.tagderintelligenz.de , you will be redirected to the first page, then the described problem appears always, you cannot navigate within the menu.
2. We have tried to implement new languages - in the typo3 editor, that's no problem, you can edit the respective texts etc., but on the homepage itself, the language change in the upper right corner does not work, and I see no possibility to change this link manually.
 I look forward to some hints from the experts! If you need any details that are not visible in the quellcode etc, just tell me.
Thanks a lot for your time and effort!
Best wishes
Isabella