I was just looking at the model too. I just wanted to point out for anybody that I used "ExplodeMove" to reveal the problem. Although Michael is much better at understanding what he found and fixed it, I found a pile of fragments in this area that the explodemove command revealed very quickly. I would have probably rebuilt the whole intersection. Perhaps all the fragments were just a byproduct of the one bad trimmed surface Michael repaired. ANyway, thought it may be useful.