Hmm, i did not have a problem with that. I have used essentially the same config file as with aolserver 4.0.10. Here are the relevant parts:
set siteroot /usr/local/dotlrn-2.2.0/
set logroot ${siteroot}/log/
set pageroot ${siteroot}/www...
ns_section ns/server/${server}/tcl
ns_param Library ${siteroot}/tcl
ns_param autoclose on
ns_param debug false