612:11018 - Backup mode is changed to full

Hi!

I have problems with incremental backups on Data Protector (6.2)... and i don't know this product.

The backup for one file server (Win 2k3 server) is planned to make a complete backup on Sunday and a incremental backup on the rest of the time.

The backup report sends me this message :

[61:11018] Could not find related full backup of the object.

Change the backup mode in a full backup

VSS is not activate on the client server. Is it a prerequisite to make incremental backup? I don't know how Data Protector works.

Thanks for your answers.

MB