I swapped the drive in my iMac when I got it around a month ago. I had fan issues (of course) and wasn't able to solve the issue. When Lion came out, I did a clean install, and the fan issue went away. Until last night. I don't know what happened between my first install of Lion and now, but the fans are stuck at 5200rpm. I'm not sure how my fans were fine for 3 weeks or so. Has anyone had similar issues?