creating a web testing scenario creates appropriate items for the host.
it is possible to delete these items directly, this resulting in the following errors when viewing web monitoring.
maybe it should be possible to modify these items through web configuration only ?

Undefined index: item_data[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:184]
Undefined index: item_data[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:185]
Undefined index: item_data[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:186]
Undefined offset: 2[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:235]
Undefined offset: 1[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:244]
Undefined offset: 2[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:254]
Error in query [SELECT MIN(t.clock) as clock FROM trends t WHERE t.itemid=] [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1]
mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource[/srv/www/htdocs/zabbix-1.6.2/include/db.inc.php:519]
Error in query [SELECT MIN(t.clock) as clock FROM trends_uint t WHERE t.itemid=] [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1]
mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource[/srv/www/htdocs/zabbix-1.6.2/include/db.inc.php:519]
Undefined offset: 1[/srv/www/htdocs/zabbix-1.6.2/httpdetails.php:254]
Error in query [SELECT MIN(t.clock) as clock FROM trends t WHERE t.itemid=] [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1]
mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource[/srv/www/htdocs/zabbix-1.6.2/include/db.inc.php:519]
Error in query [SELECT MIN(t.clock) as clock FROM trends_uint t WHERE t.itemid=] [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1]
mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource[/srv/www/htdocs/zabbix-1.6.2/include/db.inc.php:519]