Beta3 windows installer wont install

[Oriza Triznyák <dueyduey(at)freemail(dot)hu>]

I've just downloaded the zipped msi file from
http://www.postgresql.org/ftp/pgadmin3/beta/

pgAdmin III 1.4 Beta3 windows installer won't install anything.
No use if I set the target path to an existent or to a simpler one.
XP pro, v2002 Hungarian, SP2, with pgAdmin III v1.2 already installed.
Yes, I have administration rights over the system I'm trying to install on.

Sy please see what's wrong.
Thx
dueyduey