I had the same problem with my Gericom Blockbuster Excellent 7000 259IA7 (Intel Pentium M Dothan 1,6GHz) since a dist-upgrade to Gutsy Gibbon. speedstep-centrino didn't load.
A bios update to the BIOS from 25.01.2005 solved the problem.
After the update, acpi_cpufreq was loaded by kubuntu itself.
I had the same problem with my Gericom Blockbuster Excellent 7000 259IA7 (Intel Pentium M Dothan 1,6GHz) since a dist-upgrade to Gutsy Gibbon. speedstep-centrino didn't load.
A bios update to the BIOS from 25.01.2005 solved the problem.
After the update, acpi_cpufreq was loaded by kubuntu itself.