If you get an error like "aklog: unable to obtain tokens for cell hcoop.net (status: 11862790)" it may mean that your router is blocking SRV requests. If you're running djbdns locally (used by lots of operating systems for embedded devices, such as OpenWrt), make sure that the line filterwin2k is commented out in /etc/dnsmasq.conf, or whatever the configuration file is on your machine.
If you get messages saying things like "libafs can't be found" when you try to start the client, you probably installed a version of openafs-kmdl that doesn't match your running kernel. Use yum to remove the openafs RPM packages and try again.
Read MemberManual/ShellAccess/TroubleshootingKerberos for more.