Changes to .NET 2.0 Result in Breaking Changes to Culture Names
There has been a breaking change the list of culture names in .NET 2.0. This change applies to Windows Vista and anyone who has installed patch ms07-049.
The work around is basically to create a new culture with the old name that has the new name as its parent. The table posted by Shawn Steel suggests Microsoft has already does this for the two Chinese cultures. Why this wasn't done for the other cultures has not been explained.