Jon, did you ever solve these AOLserver 3.5 problems?
I just tried 3.5.1, and since it completely lacks the the
ns_startcontent command, ReturnHeaders, ad_return_top_of_page, and
various other related procs in acs-tcl/tcl/utilities-procs.tcl fail
completely.
ns_startcontent is part of Rob Mayoff's 3.3+ad13 (and earlier)
patches, and is implemented in aolserver/nsd/conn8.c
Obviously we should make 3.5.x feature complete with respect to
3.3+ad13, sooner rather than later. I know some folks are already
working on it...