Dell Quickset and CPU throttling

I have recently purchased a new Dell latitude D505 and all is well, but I don`t understand why the CPU only throttles down to 799 MHz when on maximum battery setting in Quickset app. With the same Quickset power profile(max. batt.)activated when computer is plugged in AC, the CPU throttles down to 591 MHz according to WINXP report. Now if I use SpeedswitchXP, the throttling works fine, when on max. battery setting, the CPU runs at 599 MHz, which seems right. Am I missing something here or is it something wrong with this Dell Quickset app. The way I understand power settings, max batt. profile should keep CPU speed at 599 MHz and drop even lower when the battery gets low on power, am i right or wrong? Now would someone care to explain if this is normal or what?