Did you upgrade your RedHat system lately ?
Let me guess, the two entries are
Red Hat Linux (2.4.20-19.9) and
Red Hat Linux (2.4.20-8).
If this is the case, you have two kernels on your system.
-----
Edit:
If you want to remove the old kernel, take a look at this post.
http://www.linuxquestions.org/questi...474#post420474