Pl/Tcl problem

Hello:

I'm having trouble creating the Pl/Tcl language in RedHat Linux 7.1.
When I issue the createlang command I get this:

[replicator(at)att-stgo-1 replicator]$ createlang -L /usr/lib/pgsql pltcl
replicator
ERROR: Load of file /usr/lib/pgsql/pltcl.so failed:
/usr/lib/pgsql/pltcl.so: undefined symbol: Tcl_CreateSlave
createlang: language installation failed

Of course /usr/lib/pgsql/pltcl.so exists, and /usr/lib/libtcl8.3.so does
exist also. They both were installed via the RedHat 7.1.3 RPMs (not
Lamar Owen ones). Strange thing is Tcl_CreateSlave is defined in
/usr/lib/libtcl8.3.so, which is not in the output of ldd here in RedHat.
BUT I've succesfully installed Pl/Tcl from source (7.2b4) at home in
Mandrake Linux and libtcl8.3.so appears in the ldd output for pltcl.so.
I don't know what to think, and have no idea whatsoever about Tcl for
debugging this kind of stuff.

Of course I don't think the RPMs are flawed, but I can't find what the
problem is. Any clue?

Thanks,

--
Alvaro Herrera (<alvherre(at)atentus(dot)com>)