Problem with media reproduction

When I use my new Samsung 203B for reading video content on dvds such as divx or xvid videos I hear random clicks about every 15-20 seconds. The same thing does not happen if I put the file on the hard disk.
I exclude the media player config because the reproduction is good putting the files on the hdd, process runs on high priority too. It can’t be the media because I’ve tryed with new burned taiyo yudens and mcc003 and if I run the nero DiscSpeed test I can see a nice curve with no spikes.

Using 203B official new firmware that ends with 01.
HDD is on SATA primary channel, the dvd burner is on the secondary.