Problem with accounting

Hi We have FreeRadius 1.1.4 and Mikrotik (as a NAS) with MySql as a database. Accounting works fine for all users except for one user. Authentication works fine and NAS sends updates as I specify for all users and I can't find any reason why it doesn't work for specific username. In debugging mode (radiusd -X and radiusd -x) I can see updates but MySql is empty...