I can confirm this problem on a Thinkpad T60 Core2 T7200 with Ubuntu 8.10 2.6.27-9-generic. At boot, the CPU scales nicely, but when I set the resolution for a second monitor in the gnome preferences, both CPU are set to scale 1000MHz to 1000MHz reported in cpufreq-info.
I can confirm this problem on a Thinkpad T60 Core2 T7200 with Ubuntu 8.10 2.6.27-9-generic. At boot, the CPU scales nicely, but when I set the resolution for a second monitor in the gnome preferences, both CPU are set to scale 1000MHz to 1000MHz reported in cpufreq-info.