Two Problems: 1) Safari/iTunes crashing 2) Beachball/Freeze

Question

I got my MacBook just over two weeks ago. It has been plagued with two problems:
1) Safari keeps crashing, on going to certain sites (I haven't found the pattern of the sites). iTunes crashes upon loading the music store.
- It's not a plug-in problem. The problem occurs even with /Library/Internet Plug-Ins empty. Camino with all the plug-ins enabled does not crash.
- It's a not a user-level problem. A brand new user account experiences the same problem.
- I have done two clean installs over the last two weeks, so it's not a carry-over issue from my old machine.
- It's not an isolated issue. There are threads in the Safari forum describing the same problem.
- I have completely stopped using Safari for now in favor of Camino. I don't access iTunes Music Store anymore.
2) The machine beachballs and freezes.
- Command-option-escape doesn't work; neither does control-clicking on the dock icons for forcing quit.
- The whole machine progressively locks up. Once the machine beachballs in one application, I begin to quit applications preemptively. I can do so with the first couple, but then I'm forced to shutdown the machine by holding down the power button.
- Disk Utility verify/repair checks out. RAM test with memtest checks out. (1GB of RAM are Apple OEM.)
- The freeze doesn't happen during memory- of CPU-intensive processes. In fact, it usually happens during most banal tasks (opening a finder window, saving a document, etc.)
- The only patterns I've noticed are:
-- The beachball/freeze might be related to accessing an external usb hard drive.
-- The beachball/freeze is preceded by a series of
Jun 20 17:14:17 MK-MBCD kernel[0]: (25355: ps)tfp: failed on 0:
noted in the Console.
-- There is a separate issue of ongoing
Jun 20 23:24:12 MK-MBCD kernel[0]: jnl: flushing fs disk buffer returned 0x5
noted in the Console, but I don't think this is related.
I would appreciate any thoughts and suggestions on these two problems that have been keeping me from appreciating my new machine.

Answer 1

That was exactly my point. If you've done the clean install in number of times it must be hardware related. A number of the MB have problems with overheating because the thermal grease was over applied.
I doubt the Apple store will be able to correct your problem. If your machine is still under warranty, I would send it back to Apple headquarters and have them look at it. All laptops back in 2000, Apple required to be sent back to them. This means that certified Apple technicians were not allowed to operate on laptops. I believe it is still this way. Call Apple and inform them thank you have performed clean installations and still have problems.
Ask them what you should do. You should not have to pay anything. Let us know what you find out after calling them.
Have you updated your open firmware?