When searching for a word with german umlauts ("Schröder") for the second time I get a fatal error:

Fatal error: A database transaction in eZ publish failed.

Zend Platform reports:
Source file: In file /lib/ezdb/classes/ezmysqldb.php on line 450
Error description: Duplicate entry 'schr' for key 2

I think the reason for this is the usage of "strtolower" (which depends on the locale) in /kernel/classes/ezsearchlog.php within the addPhrase-function.

If the line

$phrase = strtolower( trim( $phrase ) );

would be replaced by

include_once( 'lib/ezi18n/classes/ezchartransform.php' );
$trans =& eZCharTransform::instance();
$phrase = $trans->transformByGroup( trim( $phrase ), 'lowercase' );

the problem would be solved, I think

Steps to reproduce

Search twice for a word which contains at least one german umlaut.

LogSearchStats=enabled

Used charset: UTF-8