I am having the same problem when using THE GENERIC KERNEL. CPU is intel core2 duo T2300E. Loading the p4-clockmod module (by running sudo modprobe p4-clockmod in terminal) didn't work for me: I got an error message similar to the one which occurs when trying to load the speedstep module.
Currently the only solution for me is using the 686 kernel.
I am having the same problem when using THE GENERIC KERNEL. CPU is intel core2 duo T2300E. Loading the p4-clockmod module (by running sudo modprobe p4-clockmod in terminal) didn't work for me: I got an error message similar to the one which occurs when trying to load the speedstep module.
Currently the only solution for me is using the 686 kernel.