Still with powernowd disabled, can you try
echo 1 >/proc/acpi/thermal_zone/THRS/polling_frequency
and see if that results in the temperature being read any more smoothly?
Still with powernowd disabled, can you try
echo 1 >/proc/ acpi/thermal_ zone/THRS/ polling_ frequency
and see if that results in the temperature being read any more smoothly?