OK, looking at the pile of dead hard drives that I have on the desk beside me, I may be able to help you with this problem.
As soon as a hard drive looks bad, I do the following:
1. Put the hard drive in a towel, then in a plastic bag
2. Put the bagged hard drive in the freezer
3. Leave unit in freezer for at least three hours
4. Run to computer with frozen hard drive
5. Plug hard drive into 2nd ATA channel on the computer as quickly as possible, with no other devices plugged into this channel. Don't forget to plug in the power cable as well
6. Boot up the computer
7. Grab the files I want from the hard drive as quickly as possible, from most important to least - time is our enemy as the hard drive heats up. These files should be placed on a known good drive.
If the unit starts playing up again, immediately switch off the computer and repeat steps one to 7.
Finally, if ALL fails. During step 7, shake the hard drive while pulling the files off. (upside down, right to left - all different directions). If this doesn't work, and this is a LAST DITCH effort (and has worked for me), I tap the hard drive on the floor, first gently, then with more effort. After all, this is a dead drive, and if I can possible get one more file off, then all the better.
Finally, once it is finally dead, and you cannot get one more file off the bugger, strip it down. Inside you will find two of the strongest magnets you have ever encountered in your life. Place this magnet underneath the sump of your car. Your car will thank you for it. (it removes metal filings from the oil)
You may wish to get a copy of Unstoppable Copier and become familair with it before trying the above steps - it saves some time in the copy operation.
Phew. Some of all that sounds crazy
, but I've been recovering data for over a decade now, and I promise you everything above is gospel, and does work.