BUG #1957: Error for createlang

The following bug has been logged online:

Bug reference:      1957
Logged by:          Eduard Wulff
Email address:      abo@eduard-wulff.de
PostgreSQL version: 8.1 beta2
Operating system:   Windows XP SP1 DE
Description:        Error for createlang
Details:

I can't add any additional languages e.g. perl tcl

createlang.exe -U postgres -e plperl template1

gives:
createlang: Installation der Sprache fehlgeschlagen: ERROR:  could not load
library "D:/dapps/PostgreSQL/8.1-beta2/lib/plperl.dll": Das angegebene Modul
wurde nicht gefunden.

same for tcl

for python:
createlang: Installation der Sprache fehlgeschlagen: ERROR:  unsupported
language "plpython"
TIP:  The supported languages are listed in the pg_pltemplate system
catalog.

plpython is listed there ...

I tried changing the slashes to back-slashes in
\data\global\config_exec_params to no avail

perl or ruby works on this machine. perl is in the path.