Today I encountered an error when attempting to run a VirtualBox virtual machine. I am running 2.6.27-12-generic #1 SMP as my kernel, and I received the error, "No suitable module for running kernel found".

Reconfigurations and reinstalls didn't work, but after running the following, it started working again:

Hope this helps someone else with the same issue. Googling the problem indicates that it is an issue with the kernel upgrade making the kernel incompatible with the existing virtualbox installation.