I'm not flaming - I'm just speaking from experience. I do tons of Palm troubleshooting here and on other boards, and the fact is that many "Palm hardware problems" do turn out to be user errors. I haven't seen your actual units, and if one was truly DOA, then that one certainly wasn't your fault. I tried to make it clear that I was speaking "statistically" rather than referring to your individual case, since I don't know the specifics.
I think it actually is already well known that Palm has poor support, unfortunately. Although it would certainly be nice if they would solve their own problems, it would also be a good idea to research these things a little more yourself before buying such an expensive device.
Just because Palm decides to send you a replacement doesn't mean it really was a hardware problem - it just means that the tech support people were stumped, which, unfortunately, doesn't take much, as you've discovered.