That's exactly what it is. I don't understand it either. I bought this 250GB drive for a server at work as a temporary solution to a serious need for a large amount of space to drop some data. So, I install this drive in the server, get it up and running, create a 250GB partition, and start loading it with data. Well, it craps out and loses everything after a few hours of loading data. So, I wipe it and try again. This time checking the drive for bad sectors, thinking it may be a bad new drive. So, I load everything on it again. (about 110GB worth) and it seems to be working ok. SO, life goes on for a few days, then one day I notice I'm trying to write to that drive over the network, and I can't. I walk to the server, and it's got errors all over it "delayed write failed" and all kinds of other crap. Well, I lost everything. and this time I really lost it. LUCKILY for me, I had taken care of making good tape backups.
I lost that drive a total of 3 times. Well, I got brave, and decided to put it in the xbox since I have no use for it anymore. I let slayers format it for me, so it's f & g each about 120GB F has about 25GB free, and g has about 80 free... I haven't had one single problem with that drive. It works PERFECTLY!
I'm sure it's the partition problem, and I don't think it's specifically related to the xbox. I bet it's drive size, and software or hardware supporting that drive size.