Autodesk has released AutoCAD Civil 3D 2011 Update 1, the ubiquitous fix for a variety of issues. It includes all previous hotfixes for AutoCAD Civil 3D 2011 and those included in AutoCAD 2011 Update 1.1 and AutoCAD Map 3D 2011 Update 1.
Before applying this update, make sure that any customizations made to the user profile (such as, customizations made to the support file search paths, print file customizations, printer support file paths, redirections, custom template settings, and so on) are exported to a secure location, then imported and reapplied after the update has been successfully installed.
You cannot run an automatic uninstall to remove this update. To restore your version of AutoCAD Civil 3D 2011 to its pre-update state, uninstall AutoCAD Civil 3D 2011 and reinstall it.