I also blasted an A7V333-R BIOS (my supervisor's nephew's board) trying to go from 1005 to 1006. Here is the lowdown:
We had installed Windows, run Windows Update, just about done, and I decided to flash the BIOS from 1005 to 1006. My own board has 1006, and I had noticed at least one option missing from his 1005. So I downloaded 1006, looked at the number of bytes, which was 216016 bytes, put it on floppy, took it to the other PC, put it on the hard drive, looked at the number of bytes (still 216016), and used Asus' Windows-based flash utility, which ran correctly and asked me to shut down. I had checked both of the two checkboxes about resetting to default and reserving DMI or whatever it says. I shut down... and it would not POST. Every second or third attempt would get "System CPU Fail! System CPU Fail!" from the onboard voice.
Soooo.... after trying everything else, I POST'ed my own working board to a DOS prompt, pulled out :Q my good BIOS chip, put the misprogrammed one in the socket, and flashed it. STILL no dice. Thankfully my own chip still worked, but I wasn't about to try my good chip in the other board. We called Asus on the phone and RMA'ed the board, and I lent him my K7S5A for the meantime.
Now here's the interesting part: Amidst the many steps I tried, I subsequently went back to Asus' site to re-download the BIOS. The same BIOS 1006 was now 216116 bytes, not 216016 bytes. Is that interesting, or what?
Asus had some kind of obscure warning about not trying to go from 1004 to 1005+ using one of their three flash methods, which I think was the "Alt-F2-while-booting" method. However, I'm wondering if they had posted a faulty BIOS (no pun intended) and I just happened to use it. What are your .awd file sizes, if you still have yours? Interesting to see that Asus' FTP server, which hosts the BIOS files and manuals, is unavailable. Their German site has the 1007 BIOS but no other versions.