External USB Hard drive Problems

Hello,
I purchased an external USB 2.0 aluminum hard drive case off of ebay and I have a 60gb Toshiba laptop drive that I put in there. I am trying to use it as an external way of mass storage but im getting a few problems. I am running xp on an asus a7n8x-dlx with all drivers, the hard drive recognizes fine but when i try to write over 20 or so mb the device goes unstable and XP disables the device. So I gotta unplug it to use it again, Ive tried everything to get it working down to looking for USB filter drivers for the board and nothing is working, I have a 30gb drive here also and it does the same thing. Any help on this one would be really really appreciated.
Thanks

It sounds like the controller is having problems, possibly thermal. Have you tried removing the drive and controller from the case and testing in a well ventilated environment? Any chance there's a warranty with the case? Many of the first generation USB 2.0 enclosures were prone to have controller problems.

i alsi baught one of these from ebay and its fine.... actually i took the controller board out and changed the converter to a normal ide lead and use it as an external writer now