I think this is because Lacie don't use the same drives all the time, I read it in a review not too long ago. Can't remember what brands they said they usually ship with but I think one of them was IBM Deskstar.
I have two Lacie 250Gb USB drives and they are very different. One of them is a bit more noisy and the worst thing about it is that it "disappears" for the computer now and then for a second or two, after which the computer finds it again and starts with the autoplay thing again.
The other one works better, it's more quiet and I haven't had any problems at all with it. I use both drives for backup exclusively so I'm not so dependant of steady flawless operation, but still...
I haven't opened the things up so I don't know which kind of drive is in which casing.