With password-based logons using the ITS (for Workplace, for example), incorrect logon attempts do not cause the user account to lock (or the incorrect logon counter is not incremented).

The error generally occurs with RFC connections when performing a password-based logon to the system using an SNC-secured connection where you need to make an entry in table USRACLEXT for this, which is typically (although not exclusively) the case in the ITS environment.