booting hangs if SATA operation mode is set to AHCI

Hello,
I tested this issue with the live CDs of 0.4.6 r75965 +new usb from vgal and with 0.4.7 RC1 on real hardware. In the BIOS there is an option called "SATA operation" where I can toggle between "ATA" and "AHCI". If I select "ATA" then ReactOS boots fine. If I select "AHCI" then ReactOS hangs while loading UNIATA.sys:

So I used the debug to screen booting mode to gather the debug log:

and the backtrace:

Is there anything else I can do to help?