Don't bother fixing this. I asked our graphics programmer, Chetan, and he said that this happens because non-bumpmapped props are vertex lit instead of pixel lit. This was some kind of CSM hack, from what I can tell.
He said that in the Xen build, all props are pixel lit. So this issue should go away with the Xen update, hopefully.
Nice catch, though! Good bug hunting!
@TextFAMGUY1 You said this earlier on a different thread speaking about prop lighting issues, and I decided to post this here as to not bump the old thread. I'm wondering if this means that -staticproplighting no longer lights props by vertex, but instead by lightmaps/pixels? Because if so... wow. I can see sooo many applications for this.