External Enclosure - bad drive or bad enclosure?

[zip22]

I bought a WD Caviar black 1TB

http://www.newegg.com/Product/Product.aspx?Item=N82E16822136284

and a Rosewill external enclosure
http://www.newegg.com/Product/Product.aspx?Item=N82E16817173040

I formatted the drive in the enclosure while connected via USB. I transferred over some files, but after a few hours, the drive started getting "delayed write" errors. I used chkdsk and found it had 8KB bad sectors. I used Wester Digital's Data Lifeguard Diagnostics and the drive would not pass the quick test.

I submitted an RMA for the drive since it was only a few hours out of the box.

As a last try, I took the drive out of the enclosure and installed it in my computer. I used the WD tools to write zeros to the entire drive, and then formatted it again. now, the drive passes chkdsk fine and also passes the short test and the extended test in WD Diagnostics.

So, is the drive sketchy and should I have it replaced?

Is the enclosure sketchy and should I have it replaced?

[Albaholic]

Do you have another (known working) drive you can test in the external enclosure?

[zip22]

Not one that I would be willing to sacrifice at this point.

Actually, now that I think about it I did try another hard drive in the enclosure. it was a 2.5" laptop drive that had been acting funny and was replaced. I was seeing if I could salvage anything. I think that drive also had delay failures when I was trying to read from it, but I suspected that drive of problems before I had the enclosure.

Things a roughly pointing at the enclosure, but should I feel comfortable with the hard drive that had bad sectors while in the enclosure, but now isn't reporting any?

[Albaholic]

It sounds like you put the drive through the necessary tests and I'd be leaning toward the enclosure being bad too if i were you. No way to know 100% unless you have another drive you can test in it. If the WD passes all the diagnostics and you haven't had any trouble after pulling it from the enclosure, I think its pretty safe to say the enclosure is at fault.

[4GHZ_or_bust]

I've had issues with cheap external USB cases. At USB 2.0 speed external drives were prone to delayed write failues. When I used firewire instead on the same enclosure I didn't get any delayed error.

Google wasn't much help to me back then, 2 years ago when I checked, it seems even Microsoft doesn't understand why this problem happens but it may be related to size of data being passed through USB

[zip22]

I've also found some posts saying that the external power adapters on these can fail when the drive is pulling a lot of power. The enclosure also has eSATA, maybe I'll put the drive back in and give that a whirl.

Thanks for the recommendations.

EDIT: it's flying through 100GB of data, so i think the problem was the USB connection. it must have messed up the drive during the first transfers. glad i was able to repair it.

EDIT 2: scratch that, it started slowing down and then failed. I put the harddrive into the computer and I'm seeing if it will take all the files this way. if it goes smooth, I think I can safely say the enclosure is the problem.