I did just runt "Android System Info" from market at it reports that the CPU has two speeds 800 and 160 and it also reports that 160 Mhz is never used . Even in Idle,
Maybe a bug in that app,
Otherwise a nice app as it gives tonnes of info about the system.
I think this is correct. When I had 2.2, speed was always 800 Mhz, and there were 4 speeds available. Now with 2.3 on an HD104, there are 3 available speeds: 160, 400 and 800 Mhz. In about 10 minutes running (most of them downloading and installing Android System Info and other diagnostics software), 12% were on 160, 43% on 400 and 45% on 800 Mhz.
I also used Quick System Info Pro to have speed and CPU load information on taskbar. According to it, most of time the screen is on with no programs running gives me a speed of 400 Mhz, ~30% CPU load. Without a sim card.