an easy way to lock frequencies:

as root in x-term:

kernel-config limits 1000 1000

et voila, locked on 1000 MHz

Remember to do it at each boot or to save it as a profile, like:

kernel-config save lock1000MHz

Also, now it is stored as profile, but not loaded on boot, if you want to do so:

kernel-config default lock1000MHz

NOTE: I chose "lock1000MHz" as profile name, but you can use anyone you want, like "Totally Awesome Sweet Alabama Liquid Snake" or "RedPill" or "ImGonnaFryMyPhone", i think you understand the idea

So, all the commands above will, first set 1000MHz as min and max value to use, therefor lock it to this value. You can do this for any other combination you want. Second, we save your settings as a profile which can be loaded easily. Third, we set the new profile as default so it is loaded at computer boot.

Enjoy!

EDIT: you may want to have a look at this page for further/more informations on power kernel config: http://wiki.maemo.org/Kernel_Power