LinuxBios included VGA-Bios Mvpsd_15.rom from Epia-M Bios Version 1.1.13
Your VBIOS version number are different between Factory and Linuxbios. If you can somehow compare the exact versions that would be best.
If you can't make Linuxbios run .16 can you get (or make) a factory bios version that is .13?
Unfortanetly I can not write the differences from Linuxbios, because, there are to much :D
What are the address ranges that are different?
If we assume that Ver .13 dosen't do anything radically different from .16 then we should expect to only see minimal differences from the self-modify.
Are you sure that all of your shadow areas are setup correctly during the copy?
-- Richard A. Smith