A number of additional fixes have been included in this Service Pack, with one being of particular interest to our development partners.
If you use the Civil 3D API via COM Interop from Visual Studio 2005 (and possibly earlier versions of Visual Studio .NET), you will no longer be able to build your application once Civil 3D 2007 SP1 has been installed on your system: the installer for the first Service Pack inadvertently overwrites a few Registry keys that point to the Type Libraries for Civil 3D's COM API.
This has been addressed in Service Pack 1A, which can be downloaded from:
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=7454845&linkID=3549304
