I would point out that the errors that claim "Header is not complete" are preceeded by a full 1.4MByte download of kdelibs-devel-3.5.6-0.3.fc6.i386.rpm.
According to a (the?) yum faq I tracked down, the "Header is not complete" is supposedly caused by a HTTP proxy problem. Since I sit behind a company firewall that works well enough for the company standard windows platforms, and anything I might try from my Linux box falls in the "you're on your own" category of IT support, I decided to try the yum update from home instead (after all, it is a laptop). It turns out that "yum update" worked fine when I tried it outside of the company firewall. So if anybody is still reading this thread (or stumbles across it sometime in the future), my solution is to believe the yum faq and to (re)try the update from outside of whatever firewall you are behind. The aspects of this problem that confused me (and still confuse me) are: 1) yum update has worked in the past. Of course, our firewall situation has changed at least twice in the last 6 months, so I guess I should be surprised if one of those changes were not beneficial to me. 2) I could fetch the offending RPM fine with wget, and it passes rpm --checksig, so I really don't know why yum complained that the header was not complete. 3) When I tried yum update from inside the firewall, yum would download the entire 1.4Mbyte package and then complain that the header was not complete. When I tried it from outside the firewall, yum only download 128 or 256K (I forget, and by the time I scrolled back to look more carefully, it was gone) and was perfectly happy with what it found. So, if anybody would care to enlighten me, I would love to learn: 1) Why would yum complain about an incomplete header after downloading a full 1.4Mbyte RPM? 2) If I managed to download the RPM manually, what would I look at to see if the header was or was not, in fact, complete? 3) If I managed to download an RPM with a complete header manually, could I manually place it whereever yum would have exepcted to find it? Where would that be? (This would make sense for small updates behind the company firewall, but not so for the 300 package update I went through last night). --wpd