Version 126.96.36.199 using Firefox 15 MySql
After selecting 42 records with
SELECT T1.`dataname`, T1.`data` FROM `orders` AS T1 WHERE T1.`ordernbr` = '248753'
an inline editing of one of the records was made.
As a result the following SQL was executed
UPDATE `mybase`.`orders` SET `data` = 'Lastname' WHERE `orders`.`dataname` = 'lastname';
As a result the last name field in around 200,000 orders now have the same value !