I have an HT250 in the middle of an installation. I may have the same issue as Jeff mentions where in darker scenes I see a shimmering affect. Typically in darker areas or in darker fleshtones....very discernable artifact.
Also with a color bars test pattern shown I see the shimmer on the white and yellow sections, which may be normal for DLPs, although I am not sure. On the darker colors (blue, red, cyan) I cannot see the center focus dot on the pixels and actually see the pixels/mirrors shifting or bouncing, it is a very strange affect.
I am also seeing a purple bloom on white line to black transitions.
I have a rolling scan line that works its way down the screen although I think this is my Faroujda NR scaler, not the projector.
I have raised these issues to my installer and am awaiting resolution. It may be a defective projector...I am not sure. My friend is bringing by an Infocus DLP and his DVDO later this week, so I will let you all know if these types of issues are in his much more cost affective setup.