Comment 9 for bug 395630

removing linux-backports-modules-2.6.31-15-generic also worked for me, however, I need that installed to allow the modules for vmware workstation to build properly. So the process that I run through anytime the kernel or vmware changes is:

-Install backports-modules
-rebuild vmware kernel modules
-uninstall backports
-rebuild bcmwl (if the kernel is what changed)