This problem (and vbox problem) occurs because you are trying to use the 3.8.x kernel. Revert to using the original 3.2.x kernel that comes with precise, and it will allow the modules to build.
This problem (and vbox problem) occurs because you are trying to use the 3.8.x kernel. Revert to using the original 3.2.x kernel that comes with precise, and it will allow the modules to build.