Quick (cheeky) question: does LinuxBIOS support the 440LX chipset?
I don't know what the difference between the 440LX and BX is Buta as long as the ram registers are the same the 440bx stuff should work fine. Unless they have done something messy with the access to the SPD on the ram.
PPS output from lspci:
What superIO is on it? if your superIO supported then V1 should at least come up and try to setup the ram. If not then the differences might be pretty easy to work out by some northbridge dumps.