I have installed savecpu, however Im not and will not overclock the n900, so do I actually need that app?
I have reflashed the phone, but the problem seems still to be present,
I shall try to use another battery instead to see if the problem still occurs.

but before I do that, I have noticed something, on this n900, when not in use, its constantly around 20% at 500 mhz, I know that at stock, the min should be at 250 mhz. but this one doesnt go there. could that be the reason?