If you are having issues with your cursor freezing up (±45 seconds) in Civil 3D when you hover over a Cogo Point - then this should fix it. There is some indication that this is only an issue in Civil 3D 2011, but I cannot confirm that.
Please see the link below to a post in the Autodesk forums, so that the author gets proper credit.
AutoCAD Civil 3D 2011 Update 1 has been released. You can find the 32-bit and 64-bit downloads here. Over 40 Civil 3D issues have been addressed with this update and it includes the latest updates for AutoCAD and AutoCAD Map also.