Real-time clock running very fast on P6T/i7

I recently installed iDeneb 1.3 and updated it to 10.5.7 on my Asus P6T-based system. The full information can be found on my website (blog.am ber.org/2009/07/12/its-alive/). It includes detailed history of what I did.

Unfortunately, there seems to be a massive issue with the real-time clock (RTC). After searching the internet and this forum, the few mentions of it all revolve around fixing busratio=20 in the kernel boot. I've done that, even manually setting it on start. Unfortunately, the system seems to run entirely too fast for the clock.

For example. I rebooted this system at 5:15p and made sure that NTP updated the clock to match what is on all my other machines (and cell phone). It is now 13 minutes later, and the clock is now 15 minutes ahead. Within an hour, it will be 10-15 minutes ahead and continue to go.

If I open the Date & Time Preferences panel, then it will reset the clock to the correct time (via NTP), however it seems to quickly get out of control.

Does anyone have any clues as to what might be causing this? The system is running bone-stock configuration and no overclocking has been done.