I had this keyboard / USB fault and tried to flash the BIOS chip directly with my Nano programmer. Unfortunately the BIOS chip is the SST39VF040 which requires an additional add-on adapter to flash, which I did not have.
I decided to make a emulated floppy BIOS CD with the ECS 311 (the Advent 7*** is just a re-badged ECS 311) BIOS update containing the fix for this issue. I have uploaded the ISO for you to burn http://www.4shared.com/file/Z_-ApIWl/FLASHCD.html
I removed the motherboard from the laptop, fitted the RAM, power switch assembly, keyboard and DVD drive directly on my workbench (being careful not to short anything out!) and connected the power and an external desktop monitor to the VGA socket.
I messed about with this for ages, flipping those four DIP switches next to the BIOS chip, powering on and off, removing the BIOS battery etc with no joy what-so-ever! I was about to give up when on my last shot I did this:
I had only the AC adapter plugged in with no battery and the BIOS battery was also installed correctly.
The motherboard was switched off but the adapter was switched on.
The BIOS CD was in the drive.
I flipped all the DIP switches to ON and then OFF again.
I held F2 on the keyboard and hit the power button.
The Keyboard had been detected and began to boot the CD!
CD loaded with an error (probably my fault but not an issue).
At the command prompt i typed "afudos $331_807.bmn /p /b /n /c" (without the quotes).
BIOS flashed successfully, problem solved!
This may not work first time but I'm pretty sure it will in the end. I hope this helps anyone with this issue.