Well, this is different ... but then I'm new

What versions of rpm and httpd are installed?
yum list httpd rpm
On my fully updated test bed:
httpd.i386 2.0.52-41.ent.centos4
rpm.i386 4.3.3-26_nonptl
Also, since you have some stuff installed from smedev, try:
yum --enablerepo=smedev update
I don't think that'll help, but still...