It seems that MS decided to remove the 'File Types' Explorer feature in Vista:
http://shellrevealed.com/blogs/shell...n-Windows.aspx
And Office 2007 default settings are to not browse in same window, so you'll have to manually munge the registry to get this configured properly on Vista+Office 2007.
http://forums.microsoft.com/MSDN/Sho...iteID=1&mode=1
http://support.microsoft.com/kb/927009