It doesnt matter which name u gave to the file.. it just reads the bios date, and if it's earlier than the one u have, it just does not flash, either by floppy/USB (AFUDOS), BIOS (EZ FLASH) or windows (ASUS UPDATE), it always gave that error.

UPDATE:
Well, i did it the hard way.. I've simulated a bios update failure and used the bios recovery that ASUS implemented on this board.. I may say it works very well..LOL.. You just have to have some balls, if you know what i mean.

If someone has the same problem, just say it and i'll guide you step by step.