Abstract: A method and system for improving reliability in an optical storage system (100) is disclosed. A time shift measurement between two streams of information (150, 151) is performed during a writing operation of said optical storage system (100) to an optical storage medium (101), such as a CD, DVD or BluRay Disc (BD). Writing operation of the optical storage system is interrupted when the time shift measurement is greater than a predetermined level for detecting an irregularity in said optical storage system (100) during said writing operation, e.g. caused by a tangential shock, vibration, eccentricity or unbalance of the optical storage medium (101). Thus the irregularity, causing a faulty writing operation, the optical storage system (100) is quickly detected in order to prevent wasting a disc by interrupting recording as soon as a shock, vibration, etc. is detected by means of the measurement.