I've found several articles, posts and threads that case sensitive database collation isn't supported. Neither by 2009 nor by 2012. In Installation-progress, you'll be faced with this, latest. But I wasn't able to find a concrete reason for that behaviour.
So - what's the reason, CS collation isn't allowed?
String comparisons are case insensitive in X++. Using a case sensitive database on a case insensitive programming environment would be strange indeed.
Example: transactions may be created with currencies "usd" or "USD". Different currencies?