Inspiron 1150 password authentication screen not responding to key press except for enter key

I cannot enter the primary or administrator passwords (both of which I know) at the login screen because, it appears, the BIOS is not accepting any keyboard input except for the Enter key at this screen. Pressing ANY key, except for the Enter key does not do anything nor does the screen display the echoing of the "*", which it should if input was being processed. Pressing the Enter key simply replies that the password must be entered.

Please note the following: 1) This is NOT the Windows login screen. 2) Using an external USB keyboard does not work as the BIOS does not recognize external devices at this point in the boot process. 3) Trying to boot from a CD or USB stick wont work for reason number 2 above. 4) I CANNOT enter the Setup screen because the login occurs before the setup screen. 5) To repeat, I know the passwords, but I can't type them in.