I'm on my 3rd 30 GB 75GXP since September last year. The first one had these strange intermittent noises and eventually developed a sector error that could not be fixed by Scandisk or any other program. Confirmed using IBM's fitness test software. RMA'd it for a new one.
This one suffered from the same strange noises, but only during the first 5 minutes or so from a cold boot. However one day it decided it had enough and just died when I booted one day. I had actually swapped PS from an old 235W to 300W for this drive to rule it out (needed one for my Duron anyway).
This third and I hope final drive do not make any of those strange noises and have been running perfectly since I installed it. But if this drive fails it's bye bye IBM for life.
BTW, I'm confusing the seek noises with those strange noises I had on my first 2 drives. But it's just hard to put it in words. It's kind of like if you gently press your thumb against the top of a CPU fan while it's running, constantly every 10-15 seconds lasting 2-3 seconds...