Hi all iMac-ers! I have a new 27'' iMac. I received it a few weeks ago, and since the moment I took it out of the box I noticed a piece of dust behind the glass, however it does not really really bother me, although it a bit of a concern since I expected more from Apple. In addition, the bottom of the screen is noticeably more yellow than the top of the screen. I was wondering if this is enough for Apple to replace my unit if I do choose to bring it up to them? *also note, this computer is a replacement for a very faulty iMac (replaced iMac had dark band going through middle of screen and numerous dots on the screen depending on the colors that were on the screen).