Christoph Löffler:
model name : Intel(R) Pentium(R) M processor 1500MHz stepping : 5 cpu MHz : 600.281 ???
when you configure your kernel, compile built-in or module in "CPU Frequency scaling" the option "Intel Enhanced SpeedStep", real new manager of pentiumM (in centrino tecnology)... read help for this option... I think this is your problem...
bye :)