these devices dont keep thier time settings across power resets, it has to do with the RTC bieng built into the processor, the only way to reset it is afull power down and they didnt as far as i can tell hook up the rtc battery backup line as well (which is ok because i dought they put in the extra 32khz osscilator required for tat to work)
not sure about a reboot but a reset WILL disconnect the power, the intel docs say not to expect the time value to be sane after a reset but i find only the minutes change, not the hours or days
YMMV but perhaps ntp might be worth looking into, there is a "one shot" version rather than a running daemon that i have seen hooked up to the USB or Wlan init scripts on some machines, auto updates the time when a network cable is plugged in.
i will be quite in a minute but i think the idea with these things is that you are not supposed to reset or reboot, consider the apm -s option