Today seemed the best day to replace the hardware, so we did: the motherboard and NICs have been replaced with new equipment from the same brand (Intel), but the MB's chipset is different.
The machine successfully boots from the USB DOM, but often hang on "Loading".
When it finally moved on booting, it could find the system volume that resided on the Raid Array (same Areca controller as before).
Actually, it cannot find the RAID controller at all, e.g. it does not appear in the hardware list, although it is properly recognized in the BIOS.
It appeared that the Areca Firmware was too old (version 1.46 from 2009) and needed to be 1.49 or above to solve some known MBR issues.
After upgrading firmware, all went well!
Last edited by Arcesilaus; 09-23-2012 at 02:30 PM.
Most if not all the RAID controller companies, recommend to update the Firmware, due to multi things, one of that things is the compatibility with the new drivers for the controller itself. We also recommend to update the controller Firmware.