Cause to repeating HD failliure?

Question

The PB was bought late feb 2005, and the hardware is still as delivered from factory, except that Apple during the year of warranty has replaced the HD three times (in april-05, august-05 and january-06), the logic bord once (august-05), and recently the battery was replaced by the exchange program.
I'm a writer. I use the PB as a stationary, on flat surfaces. I don't use it in my lap, on pillows or other stupid places. I don't carry it around much, and lately I don't use it professionally anymore. I don't dare. I've allready lost to much writing in the freezer.
The HD installed in jan-06, worked flawlessly for three months, then it started to freeze occationally, with shut-down as only option. In these situations I had to remove the power and battery for 15 minutes, else the PB wouldn't recognize the HD on start-up.
Zeroing the drive and reinstalling OSX didn't resolve the problem, and the freezes has been increasing ever since, in the end freezing after only 5 minutes of operation, and now it sort of died.
Sort of, because the HD's still there. Hardware test says nothings wrong. But I can't complete a zeroing or reinstallation of OSX. It starts, but during operation it sort of looses contact with the drive.
All drives have been Toshiba, which have a bad reputation. But maybe its not the HD, but something else that causes the HD to fail? Does anyone know of other hardware issues that are harmfull to the HD? Maybe the faulty and very hot battery could have ruined the HD?
Cheers - Tone

Answer 1

My problem is that the HD isn't wholly dead yet. I managed to create a partition in the other end of the HD, and install OSX. It runs for about 10 minutes and frezes, which renders the machine practically useless but not dead.
Cince I didn't feel that I ever recieved a working PB from Apple, I didn't invest i appelcare. But I'll call customer and talk to them. There should be a warranty on the HD (replaced in jan-06).
Only, I don't think its the HD's fault. 4 succecutive HD's lasting from 3-6 months on this paticular machine seems odd to me. I allso own an Ibook, two PC's and three ext HD's, and I have had no problems with any of these machines ever. I allso know several people with the same PB model as mine, which have no problems at all.
SMART-status says the drive is fine, and the problem seems to be heat/power related. Upon frezing, the PB has to be shut down and rest (cool off) for 5-10 minutes before rebooting. Else the machine won't recognize the start-up disk, and disk-utility will see only the drive itself but not the partitions on the drive.
So to me, it seems like the heat from operating the PB causes it to lose the connection to the HD. Whether its the HD or something else in the PB that freezes up I can't say, but Apple replacing the battery, the motherbord or HD hasn't cured the problem. So, anyone with similar problems, or a clue to what's wrong?