Just received mine yesterday and got it running. Haven't gotten to really play with it yet aside from adjusting 'basic' options and upping my RAM's vDIMM.

So I've been reading about the 'Northbridge Strap', and from what I can see, it's the value that 'classifies' what 'quad-pumped' FSB rating you fall under? Depending on your OC you might get bumped to the next 'tier' which may have an adverse effect on performance until you can up the FSB enough to 'match' where it was with the originial strap.
And you can't control that setting with this board?
Sound about right?

@tomati: no squealing here either, friend. Reason I purchased this board was because my Infinity 965 was a piggy and I couldn't stand the sound (louder than my HDDs & VGA fan), I didn't want to pay $300 for the DFI NF 680i, and frankly, I don't like Asus or Gigabyte boards much. I was happy to see that Abit released a P35 board, and even happier when I found this thread about how bada** it is too!
If you return your Infinity grab one of these. It's not much more expensive and is every bit a killer board.