I store the text in db like this: "Benutzer%20l%26ouml%3Bschen" (uriescaped_utf8), when I receive it, I uriunescape it and then I compare...
It looks like the value stored in the database contains a HTML Entity, so when you retrieve and uri_unescape it, it is "Benutzer löschen", not "Benutzer löschen". 
uri_unescape( Benutzer%20l%26ouml%3Bschen )
=> Benutzer löschen

and

uri_escape( Benutzer löschen )
=> Benutzer%20l%F6schen

uri_escape( Benutzer löschen )
=> Benutzer%20l%26ouml%3Bschen

[download]
It looks correct when you print it out to the browser, but if you view the source of the HTML you will see the problem.

One way to solve it is to html decode the value before making the comparison: 

use URI::Escape;
use HTML::Entities;

my $db_value = uri_unescape( $aText{'1530'} );
decode_entities( $db_value );

if ( $p_sAction eq $db_value ) {
    ...

[download]
In the future, when you are saving the values to the database, you could remove the entities before uri_escape.

Update: minor edits.

In reply to Re: Decode umlauts on CGI-parameters by tangent
in thread Decode umlauts on CGI-parameters by Yaerox

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