Civil 3D 2012 Update 2 has just been released. You can download it from the following Autodesk site:
There are lots of nice fixes that prevent Civil 3D in specific situations. We’ve gotten a few calls regarding COGO point label rotation coming from older drawings being reset, that has been fixed. There’s been lots of stability improvements too. Some of the areas updated for stability are feature lines, grading, and pipe networks. The stability of the AutoCAD Audit command has even been improved.
There’s quite a lot of other specifics, so make sure to check out the Readme. Hopefully any problems that you may have found have been taken care of.