Yup I know Phone resets the CPU to 600 MHz - not sure if anyone with more technical insight than I possess could confirm that it needs 600, but that's what it pegs the CPU at...

I'll test video capture today....so far though (and obviously YMMV etc etc) my settings work just fine for the daily tasks (especially at work) that my N900 ambles through.

Fortunately it's easy enough, through QCPUFReq, to open up the throttle with two clicks.

When needed.