The KeyListener does not work on Safari 4.0.4. Way to reproduce. Go to sample
with Safari 4.0.4 on any Mac OS
and try to log in using the login dialog box. You will notice that no matter how many characters you type in the login box for password and username the Login button in never enabled.

This is different behavior than the behavior of any other browser.

This may be a problem on Windows as well but I do not have Safari 4.0.4 on Windows to test.

I have verified this is a problem on Mac Book Pro running Snow Leopard and iMac running Leopard.