The firmware is tied very closely to the phone's hardware, that's why it's firmware, not software.
It's difficult to say exactly how it can effect physical interaction, but all I'm saying is I can easily reproduce this issue on OS4 and I never had this happen on 3.1.3 on my 3GS. It's the same physical interaction.
And another reason I am fairly certain this is a bug is that in the advertisement the phone is being held this way... If Apple knew this was an issue, they wouldn't have made the ad like that. If they did, they deserve to be sued for false advertisement. So I think this is unexpected and firmware related.
Well no offense to you, but there have been at least 2 RF engineers that have looked into this and they strongly disagree with you.
I understand your thinking on this as I initially had drawn the same conclusion. However, after the last two day of testing over 12 different iPhone 4's from different batches, along with some 3G and 3GS's I have to say again we are dealing with 2 issues here. But that is mere speculation because ONLY Apple knows their design and what they are doing in terms of RF and antenna etc.
No one would be more delighted if Apple could put out a firmware update that suddenly and miraculously fixed this issue. I think on the iPhone 4 they can make the issue better, but can they fix it?
Also Apple has never put out cases or bumpers for these phones. Suddenly this year they put out a bumper? Is that coincidental or because they knew? I'll let you and others decide that.
I would love nothing more than them to release iOS4.01 next week and this problem vanish on the iPhone 4, but I think they can only make it a little better and the rest will have to done by using bumpers or a case.
By the way I in no way feel this is detrimental or unsolvable. I just think there are going to be a lot of folks that are going to feel like saying use a case or bumpers as a means of resolving this isn't going to be acceptable. I always use a case and so for me it truly isn't an issue. But we like tinkering so we've taken this up for a challenge. We are done now and will just enjoy our phones.
Also I am not an RF engineer and to be honest I don't know much about it. I've been going by what others are saying. Hell for all I know you could be absolutely correct and Apple will release and update that totally fixes the issue. I hope it is so!