[Zope] GUF Authentication Problems

[Mario Premke]

Hi,
I cannot authenticate users with the following method:

<dtml-in "sql_get_password(xlogin=username)"> 
	<dtml-if "password==_['sequence-item'].real_password">
		<dtml-return "_.int('1')">
	</dtml-if>
</dtml-in>

<dtml-return "_.int('0')">

The ZSQL-Method works as well as the former default method
(user='jorge',passwd='secret') did.
This above code comes from the Zope How-TO's:
http://www.zope.org/Members/hippy/GUF_SQL_crypt_1_2

Any ideas will be appreciated as I have no idea any more
what could be wrong...
Thanks
Mario