I bought my D90 from a friend earlier this month and recently discovered a hot pixel. It shows up at all shutter speeds and every ISO I've tried. Here are 3 pictures to show you what I mean. all 3 are at f/4.2 with a 1/5 second shutter. 200 iso 1250 iso 3200 iso He purchased it in September of 2008, so the warranty is up. Is there anything I can do about this? I wouldn't think Nikon would fix it for free. Has anybody yielded positive results with these?