I'm having a similar problem. My girlfriend's computer currently runs my old Epox 8KTA3 motherboard. This morning, I decided to go ahead and try patching the most recent BIOS update. I've been doing flashes for years, and never had a bad one (until now). I downloaded the bios exe file, and extracted it to a blank floppy.
I went ahead and used the the ALT-F2 command at boot-up to flash the BIOS. I've used it without problem on this 8KTA3 with no problems before, as well as my system's motherboard, the 8KHA+. The flash appeared to go fine, and the system rebooted. However, upon rebooting, I got the screen saying:
Award BootBlock BIOS - 1.0
blah blah blah
ROM Checksum Error
Reading media type Drive A...
INSERT SYSTEM DISK AND PRESS ENTER.
It's not word for word, but you get the idea. Anyhow, I had no idea what the bootblock was at first, so I did some research. I've been working on this for hours now. I've come to the conclusion that maybe I have one of these BIOSes that Rainbow spoke of, that has a corrupted BootBlock on it.
I've tried using 3 different floppy drives. I've tried using the same drive to create the system disk with as I try to boot from (to ensure maximum readability of the disk). I've tried Windows ME, 98, and even MSDOS 6.22 (thanks for the bootdisk.com link). I tried naming the BIOS file as old.bin and origin.bin (have seen some BIOSes that require a particularly named file to do the emergency backup flash). I found an old system in the garage (486, full ISA bus), and tried using the ISA video card from that system (I've read everywhere to use an ISA video card for the bootblock flash, but the results are the same, using it or an AGP video card). After puting the AGP video card back in (the 8KTA3 has only 1 ISA slot, and it's lucky to have that), I pulled the ISA I/O board out of the old system and put it in the dead system. Even using the ISA floppy controller, no luck. I tried making a 720k floppy, but none of my floppy drives seem to support it (I tried every possible way to force it).
I guess what it comes down to, is that I'm SOL. I'm going to try to hunt down a friend tomorrow that I think has an EEPROM programmer. If he doesn't, I'm going to call every local computer shop and see if they won't sell me one of the chips out of their boards, so I don't have to wait for one to be shipped. If all else fails, I order a new BIOS chip online. Should I try ordering one from Badflash.com or another 3rd party BIOS vendor, or should I order one directly from Epox themselves? My main concern right now is getting her system back up and operational ASAP, if that ultimately means buying a new motherboard tomorrow, and setting this one aside for a 5th operational system

If anyone can offer any other advice or suggestions, I'll gladly listen... Thank you in advance.
PS- A couple questions I forgot... Is it worth the risk to try hotswapping, if I find a friend with a KT133A chipset motherboard? What about using my 8KHA+ to try hotswapping? I have several other motherboards with PLCC socketed Award BIOSes. Is there a way to force the flash program to write to the BIOS, regardless of whether it "thinks" it matches? How hard would it be to make my own EEPROM writer, or does anyone know any places in the Dallas, TX area that will flash an image to a chip? Please, if you are reading this, feel free to answer whichever questions you might know the answers to... My goal is to get this system up and operational within 24 hours if at all possible. Thanks again in advance.