I had the 1.20E AHCI ROM in my GA-EP45-DS3 board and that AHCI ROM should work for the GA-EP45-DS4 as well?
It's actually originally modded by Acebmxer. :)
Intel Raid Rom 188.8.131.521
But if I'm not mistaken the IRST 184.108.40.2067 added to the ga-ep45-ds4MOD_6_21_12_f9 means the AHCI ROM now is 1.20E (just not the super new version that's for the P67 boards)?