I noticed that when I for example browse this forum while rendering an image, the rendering slows down a lot. Even when doing nothing in other programs, this seems to happen. From the moment max goes to the background the rendering slows down. I noticed this while rendering a simple animation. Frames took 30s, then I read some stuff on this forum, went back to see the progress and saw that lats frame took 1m. The next frame while i was watching again was only 30s. There are no big changes or something between frames that could explain the slower rendering time.
While writing this, I went back to my anim and now the last frame took 4m30s! But I don’t know if it really took that long, maybe it’s just max saying that it took this long or something.
I have the latest flash version installed already. Your computer may have a different processor and graphics card. The banner is still jumping between 60 and 85% here.