I've found welding to be sometimes unstable, so it's not just you. Sometimes exiting and restarting helps, sometimes not. Computer voodoo strikes again. Here's something I've done when I can't get a particular weld to work: I link two vertices I want to weld, then I go into the properties tray and make their xyz coordinates match (linking allows you to see both sets of coordinates at the same time). Then I save before I weld. If it crashes, at least my model looks like the point has been welded. Hmmm. It occurs to me that maybe one could weld by hand, just by linking vertices, and deleting the duplicate. Like, say you have two triangles and you want to weld the top point of one to the top point of the other. You could link each of the bottom points of one triangle to the top point of the other, then delete the the top point of the first one. Sort of a manual weld, if you see what I mean. I wonder if that would work... if so, it might be a solution when a particular vertex object is being weld-cranky. --Terri