Fedora Frozen?

[Ki Song]

Something weird is happening to my Fedora Core 4 box. Just to let you know,
I am not running any GUI. Primarily using it as a mail server.

For some reason, the mailserver that is running on it (Postfix) is working
fine. I can even log into the box using SSH from a remote location.

However, after about a day or so, when I try to login to the box directly
using the keyboard that is hooked up to the machine, it doesn't do anything.
By that I mean that the login: screen does not show up at all.

Usually, I just press the Num Lock button and the Num Lock light on the
keyboard lights up, but that doesn't even work.

Any ideas?

Regards,
Ki