There was no speedstep options in BIOS.
After seeing the clock speed in "Control Panel\System and Security\System" never change from 2.3 Ghz and it seems speedstep was not working. I also changed the Processor Power Management in the Power Options/Advanced Settings - this didn't seem to do anything.
I ran CPU-z like you suggested. Then I got 800 Mhz
But after running SuperPi, it stayed at 800 :S It took 3DMark06-CPU test to finally get 2.3 Ghz...
Since the notebook ran well at 800 Mhz and stayed at 800 until all cores/threads where under high load, this makes me think the i5-2410M run VERY well at low speeds and runs VERY fast at high speeds. blows away my old Core Dual.