If you check your AutoCad Civil 3D right top part you will see that there is an update to the software. Yes, Civil 3D 2013 SP1 is available. I could not find it in the list of service packs to be downloaded yet, but I updated it thru the self update function of the software. Be sure to check the readme file for the issues that are fixed with this issue of SP. Trust me, there are lots.
Here is the link to the readme file: http://updatesdl.autodesk.com/updates/files/autocad_civil_3d_2013_sp1.htm