Can't change CPU settings? Any ideas? topic

Hi all after wiping my nook and starting again I've had quite significant battery issues. I've now followed the general advice out there and removed as much as possible etc so far so good but according to cpu spy and nofrills cpu it's still using 600mhz and 800mhz despite me using nofrills to lock it to 300. Anyone any ideas on why it isn't working? It shows the success popup but just doesn't mean actually stop the nook using the higher speeds.

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