Description of problem: The tc command looks for the netem module in /usr/lib/tc but it is installed in /usr/lib64/tc. Version-Release number of selected component (if applicable): All FC5 updates (inc testing) current as of Sep 7, 2006. Creating a symlink from /usr/lib/tc to /usr/lib64/tc allows the use of netem.
This is already fixed in rawhide - FC-6