I can't believe Auto Detect Contact On Attach is turned on by default.  This is a terrible choice for users with associative CAD interfaces who don't realize it is an automatic feature. They bring in their geometry the first time, get a model working, usually by deleting many unhelpful contacts. Then they update the geometry and get hit with all those old contacts that they don't want and it's hard to discern the "new" contacts from the ones that were carefully checked during the model building task.