God knows why Apple sell the LaCie drives in their stores! They seem pretty terrible to me.
I had one once - my advice, DON'T bang the table it's sitting on - not only did it screw the drive but it screwed the PB it was connected to (running OS 9).
Prior to that, it corrupted the 6GB or so I sent to it - I blame the software it shipped with ("Silverkeeper" i recall) as much as anything - don't use that stuff, just drag & drop.
A couple of years later, I connect it to a 10.2 machine, thinking that the stability and advancements of the OS would enable me to fix stuff and maybe use it again - not only did it not work, but OS X got so badly screwed it seemed that I had to completely re-install it! (Drives would not mount, etc - a bloody mess!) I didn't even transfer any data that time!
...
So, a few weeks ago I got to the point where I had 5GB left (from 80) on my iMac. Knowing my only option was an external drive I got a "Maxtor Onetouch II". After a few initial problems (the so-called "backup" software refusing to open) I just dragged across what I could (mostly my music collection ~30GB - a lot of audiobooks!), made sure the files were running on the external drive (by changing iTunes prefs etc) zeroed the internal drive and re-installed Tiger.
So far (fingers crossed) NO data corruption, NO mounting issues and no other problems. Oh, and of course, Tiger is running a lot faster than before (it was an update of 10.3, which was an update of 10.2!). I recommend the Maxtors over the LaCies any day.
Having said that the LaCie CD burner I bought a while back works great!
Oh - and I now keep the Maxtor on a small cupboard I have under my desk - it is in no way touching the desk surface - I like it that way!