I've got a n900 I got from eBay --- was seemingly new-in-box. It worked fine for a few months, but it's developed a 'jitter' to it's sense of touches on the right side of the screen.

Am I going to find that taking it apart and reseating connectors is the answer? Is this a known or common problem?

yup you can solve it that way i just solved my loose slider . You need to push the clips that hold the plastic frame to support the digitizer. Dont try to open that plastic frame its damm hard you will break it if not careful. You need to push those 6 clips by a needle or small screw driver that hold it and you are done if your slider is loose just elevate the springs a little and press them then at the middle right side there is the slider lock press with a flat screw driver at the end . Then do not close the slider put the 2 screws tightly release it and screw just be careful deassembling it .

Is there a post with a better description and/or photos. I recall that the ribbons of wire in the device seem to aggregate under two beige plastic clips --- I'd like more data on this problem.

I now have two n900's with this problem.