Dear Raúl,
i haved tried the following commands in ds/shell
set dir [acs_root_dir]
ns_eval source $dir/packages/acs-tcl/tcl/request-processor-procs.tcl
on the server, which comes closest to your configuration, and it works fine:
Server: 4.5.0p1 (AOLserver)
Tcl: 8.5.9
XOTcl: 1.6.6
Tdom: 0.8.3
libthread: /usr/local/aolserver/lib/thread2.6.5/libthread2.6.5.so
Tcllib: /usr/local/aolserver45-HEAD/lib/tcllib1.10
acs-kernel: 2008-10-03, 5.4.3
xotcl-core: 2011-01-14, 0.118
xotcl-request-monitor: 2008-10-04, 0.42
xowiki: 2011-01-14, 0.136
xowf: 2010-06-17, 0.30d
i would recommend XOTcl 1.6.6 and xotcl-core 0.118