Fedora Core 3: Need to Install org-x11-devel ( error:...Header...signature, BAD... )

[downplay]

I need to install the development package into Fedora 3.

My command results in the error below:

error: xorg-x11-devel-6.8.1-12.i386.rpm: Header V3 DSA signature: BAD, key ID 4f2a6fd2

I'm not even sure I have the right file. This one I downloaded from a mirror linked from:

xorg-x11-devel - X Window System application development package

How do I know if this is compatible with Fedora 3?

Also, I don't seem to have PGP installed. The error looks like some type of security
signature. Could lack of PGP be the problem?

[pitbull7270]

The Unofficial Fedora FAQ - Fedora Core 3 this will help with the error.