I had a RAID array running (stripe) using 2 new Samsung 250 gig SATA 2 drives, and Nvidia RAID. My mobo is Asus A8N Sli (an old version). See my sig.
About a week ago I kept getting a little windows message saying something like 'found new drive'. I thought perhaps there was a loose cable and it perhaps kept detaching itself. I now now this isn't the case. Anyway, this message kept coming up and the drive kept disappearing and reappearing, and working fine when it was there.
Then yesterday I was opening up a folder on the drive and it was empty. At first I thought the drive was being slow but then I got another worrying dialog such as this:
I thought "YELP!". Anyway the drive was still visible but every folder I clicked on was empty and I kept getting those messages. I clicked on properties of the drive and Windows is telling me that the SAME amount of data is stored there. So perhaps there is just some problem accessing it and it's not gone. Anyway what's bizarre about the dialogue is I wasn't trying to "write" anything, just view.
A few reboots later and the drive doesn't show at all, and no dialogs. The DOS screen on bootup says it's there and healthy.