wy aren't you using the 5035 bios??
ure best bet would be to have 5035 bank 1/2 flashbios cromwell 3/4 512kb each to make 1mb bios file. i have never used a dummy file and it's always worked but with flashbios 3.03 i just type in xbox ip adress in internet explorer and trandfer it across

the open up the ini file make assorted changes. or use a toold for it then dump it in root of e or f drive need to ftp in so use evox to do it