Well... I have had my DLP projector now for a little over a month, and I can happily say that my headaches did in fact go away completely after about the first 2 weeks and I hardly notice the rainbows any more. When I do, they no longer really bother me. I was very worried at first, because I appeared to be very susceptible to rainbows and headaches, but I've been headache free for two weeks and only see rainbows every once in a while now. So for those of you susceptible to rainbows, there is hope.