Problems with Maxtor HDs in G5?

End of May, I bought a PMG5 2.3GHz with a X800XT as a BTO, and 2GB of RAM, for a typical usage: video.
After opening a FCP project that I had created on my previous computer, a pop-up menu appears warning: images might be lost with the following sentence: “some images have been lost during loading/reading”. Knowing that everything was working smoothly on my previous Sawtooth Bi-500 makes any comments such as upgrade your computer to a more powerful unit useless.
So, I create a QT movie in DV format from a DVD. when reading it, same thing, images freeze while being read (to continue, one has to press stop, then play)
So I contact my apple reseller and based on his advice I update the graphic card firmware.
Nope, nothing helps. Then he lend me a 250GB HD from his own stock on which I save the video files...and freezing problems are solved!!
Thanks to this HD, I have tried everything: reformat the original drive, partition, inverting SATA connections, etc... at the end it clearly shows that the original HD is the problem, a Maxtor.
So, I contact Apple and thanks to my warranty I obtain a new HD, the same: a Maxtor, model 6B250S0 revision BANC1E50, and as I could fear it, same problems. impossible to maintain a DV streaming.
So, either I am unlucky guy, or there is a issue with this HD. It could be why, the last configuration are equipped with Western Digital HD...