disappearing data on Scsi drive

OK ... with the mystery of the magnetic HD solved, here's a fresh description of my final problem:

9g IBM UW SCSI drive. Data storage only, no OS.
Adaptec 2940uw card. Also connected is a SCSI CDRom drive (this is working fine).

2 nights ago, I boot up and everything is fine.
I reboot 5 minutes later and suddenly the 9 gig
shows no data. However Win98se still assigns a drive letter to it. Computer properties says: "zero mb used, zero mb available". Explorer
shows the drive letter too but also says "drive not available".

So question 1: Can I assume at least that the partition is INTACT because Windows assigned a drive letter?
Q 2: What's the best way for me to check for data?
Q 3: Any ideas on either how the data can suddenly disappear or why the drive is not being
read correctly?

Thanx
Bill

I

(Sorry about that.)

Update:
I viewed the drive's info using fdisk which shows
the partition is fine. I then attempted to install
Windows 98se on it, but setup says this drive is not formatted correctly for it. As I said before, this drive WAS formatted under Win98se and has worked fine as a backup until now. I can't format again like setup suggests because the drive contains CRUCIAL data.

Any ideas?

Thanx.

See if you can see the contents in dos. If you can then save it somewhere. This has happened to me a couple of times in the past, usually right after upgrading or updateing an application on that drive. Also have only seen it on systems that have both IDE and SCSI active. Have no clue why this happens. Adaptec said it was a Mickey Souse problem. Wish I could tell you more.

Thanx jbar,
No, I can't see anything in DOS; the computer
acts as if I created a partition OK but did not format yet.
I just don't understand how it can be running fine for a year, and 1 minute later show NO DATA.
I really need to try everything before I format
because the data is really important. My last backup was 3 days before.

I've just been using a data recovery program, which has just saved my bacon and may be useful here.

You'll find the demo download at the following link: <a href="http://www.ontrack.com/easyrecovery/" target="_blank">http://www.ontrack.com/easyrecovery/</a>

Unfortunately this will only show you if it can recover the files. You will have to buy it if you want to actually recover them.

Hope this is of some use to you.

Thanx all.