For a history of the problem, see this thread: http://forums.macrumors.com/showthread.php?t=329551 I recently took my 3-month-old Mac Pro in for service, since the fumes were not dissipating and I could no longer leave the office window open due to the colder weather. Based on suggestions from others with the same problem, I told the tech that I wanted the thermal compound removed from the processor heatsinks and the bare minimum of new compound applied once they were clean. When I picked it up, he told me that "there was a LOT of excess thermal paste on the processors." I've had the machine back for a week now, running daily to burn off the smell from the new paste. As of today, the smell is completely gone. I don't know what's in that paste, but I hope it's not a health hazard. It sure did burn the back of my throat every day for the last 3 months. Hopefully, Apple has, or will, correct this problem on future machines. Christmas wish: Someone will develop a "green" non-toxic thermal paste. Good luck to others with this problem.