I noticed this quite by accident the other day while rendering out
an After Effects animation I had done. I had made a spelling change in
one of the graphics, and re-rendered a composition I had rendered the
day before. When it was finished, I noticed in the Render Queue that it
had taken 15 minutes longer to render than it had the day before. This
seemed odd to me, as like I said, all I had done was changed the
spelling of one word in the animation. It turns out that Safari is responsible. Read on for tests and explanation.

Note: This article was written in February of 2006, so obviously it applies to OSX Tiger, and not Leopard.