Quote Originally Posted by bing
It is normal on any setting other than "grandma"/stock mode, since the Asus Bios team decided to reboot the clock gen chip to apply those non standard clock setting.

Yep, its bad for PS and HD, but request for fix already submitted and it seems this issue is not in their priority list yet or couldn't be fixed at all, time will tell.
I don't think this is just an Asus thing. Other boards including the Bad Axe will sometimes do it, especially after a strap change in the BIOS. I think it's the chipset.