We started with a white dot here and there and now they practically cover the whole screen and it's difficult to see the picture.
I called Mitsubishi Consumer Relations at 800-332-2119. I gave them the model number and serial number. The best they could do for me was send their service people to my house to replace the part, which they said is "free" but we have to pay $200 +tax for "labor."
We have not made up our minds, as we are considering just buying another tv--definitely not a DLP model. The white dot problem seems prevalent in several different brands of DLP models.