If you are getting blank pages, or if others are, you should check the following in your language pack files:
Check for Syntax errors in the php code. A missing " or ); will halt everything.
Make sure that none of your translated files contain a BOM or Byte-Order-Mark. (will not be visible when viewing in utf-8 mode). ie. if you see  , it needs to be deleted. Note: Notepad creates a BOM by default when saving as utf-8, try removing the  with an ASCII php editor.
Make sure your {Language}.php file has the correct CHARSET and that your browser is detecting it as such. (usually it's View -> Character Encoding, in the browser)
If you still get a blank page, login as admin and add ?[debug] to the URL. example: news.php?[debug] OR news.php?[debug]item.41 - you should then be able to see what the php error is.
Hope this helps. Update:
The no 1 thing you can do for checking your language pack is to use the tool that was made for this purpose. Go to admin -> languages -> tools.
Yeah.. from what I can tell, on some systems it halts the script, on others it ignores it and runs properly. Also, if you have a BOM in your script, you will get a warning when you try to validate the xhtml of the page at W3c.
I have this problem.. I dont have any problems with white pages till I updated my site from 0.72 to 0.75. No content pages can't be seen. Why everything goes fine with version 0.72, but with version 0.75 not? Also ?[debug] doesn't help
Hi, I found out my signup.php does not work in my language, as I see on the top, I should check all language files, shouldn't I? Will it help? English lang signup.php works properly.
and it might be related also to Prefs / no menu on right side like security, (in English right menu is shown) Thank you