Konqueoror in KDE-2.2.1 does not scan netscape plugins correctly, missing some like plugger.so. This is not a RedHat bug as it is reported by other people to kde.buga.org as well. Copying nspluginscan from the KDE-2.2 rpms to replace the one in 2.2.1 solves the problem!!
Please verify this with a newer version of Red Hat Enterprise Linux or Fedora Core and reopen it against the new version if it still occurs. Closing as "CURRENTRELEASE" for now.