Curious what URL you are using - the password has never auto-filled for me when I was running IE6, and now does not with IE7.
It has never autofilled for me either, I have mozilla...I'm glad it doesn't though, since I have a laptop that could be stolen easily...
I'm using IE6 and it also auto fills for me .. started working a few months ago. Edit: double click on your username .. then click the empty password field .. and it should work.