[K-Bat]

I really need your help! This post is kinda long, but I want to provide details. I'm suddenly experiencing extremely slow hard disk access on my 9-month-old PB 15". Some basic info about this PB:
OS: Mac OS X 10.3.7 (7S215)
CPU: 1.5 GHz
HD: TOSHIBA MK8026GAX (80GB, 5400rpm)
RAM: 2GB

I noticed this problem this afternoon when I tried to open some jpeg files on Photoshop CS. Everything became so slow. Then I realized that this was not a Photoshop-specific problem; any operation that "writes" to the hard disk brings the PB to a crawl. The last time my PB was running fine was before dumping these jpeg files from my digital camera.

I run an Xbench test, and the results clearly show some problems (I stopped the test before finishing it because getting to this point already took an unusually long time):
Xbench 1.1.3 results
Disk Test 0.91
Sequential 0.91
Uncached Write 1.16 0.48 MB/sec [4K blocks]
Uncached Write 0.75 0.31 MB/sec [256K blocks]

I also ran a series of disk maintenance programs (Repair Permissions, Repair Disk, Disk Warrior, and Apple Hardware Test), but they all finished ok without reporting any major problems.

Right now the PB is booted from an external FW drive and working just fine. I also noticed that "reading" from the internal HD seems to be ok (I know this because I just copied some large files to the external FW drive and it didn't take long to do this).

So I guess the problem is related to "writing" to the internal HD. I have three questions.

1. Is my hard drive dying (if not dead)?
2. Are there any other hardware testing programs that I can run to diagnose the problem?
3. What's the average turnaround time to repair this kind of problem at Apple?

Thanks very much, and I'd really appreciate your help!

K-Bat

[K-Bat]

UPDATE: I reinstalled the OS twice, and my PB somewhat regained performance. Not perfect, but usable now. However, I brought it to a nearby Apple Store today to see what they have to say. After listening to my story, the Genius said he would go ahead and replace the hard drive for me, so I left my PB with him. I was pleasantly surprized by his offer because during the whole conversation my PB was running normal(!) and I was expecting to hear "well, it seems ok to me..." He even hinted that if I send this to the repair factory they woldn't perform a service for lack of apparent symptom. Thanks Genius!

[alphasubzero949]

Was your hard drive making any "clicking" sounds? If so, that is a sure sign of failure.

[K-Bat]

I didn't hear any clicking sounds, but I did hear slight but noticeable humming coming from the HD.I can't remember when it started. I still consider myself lucky, having not experienced a single hard disk failure until this one in the last 12 years (all Apple). The best part is that I'll be getting a new HD installed under warranty!