Description of problem: Following most recent updates are not signed causing yum to fail... tcpdump-3.9.4-10.fc6.i386.rpm libpcap-0.9.4-10.fc6.i386.rpm
not a yum bug, yum is doing what it should be doing, I think.
Sorry - you are right it is not a yum bug but a bug in the individual packages
Packages are now signed.
*** Bug 232523 has been marked as a duplicate of this bug. ***