Hey ,
Probably u've installed tcl twice.
I mean 2 different paths exists.
So type "whereis tclsh" then u're able
to get diff. path installations of TCLSH
use appropriate one to login in TCLSH.
ex: /usr/local/tclsh or whereever it is installed
and test so called command
"info exists tcl_platform(threaded)"
Ashwin