BUG #1957: Error for createlang

The following bug has been logged online:

Bug reference: 1957
Logged by: Eduard Wulff
Email address: abo(at)eduard-wulff(dot)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.