psql: no chance to enter password in certain situations

OS ist Windows XP Prof, PgSQL version is rc5 via windowsinstaller
When trying to restore a db, psql does not ask for the password but
responds imediately with an erromessage as in the following example:

F:\doka\bak>psql -U postgres template1 < pg_dump_all_2005-01-11.txt
Password:
psql: FATAL:  password authentication failed for user "postgres"

However, in the following situation the password can still be entered as
expected :

F:\doka\bak>psql -U postgres template1
Password:
Welcome to psql 8.0.0rc5, the PostgreSQL interactive terminal.
......

Regards
Christoph Becker