Glue points stopped working in visio 2010.

[patrickivy]

I can't find an answer to this problem anywhere.

I made a little custom shape that is a rectangle with a glue point in the middle of each side. Sometimes I need to glue the shapes together, top to bottom. All of this was working fine.

On one of my current projects, the number of rectangles on the screen is getting high, and the following behavior has developed:

If I drag a new instance of the rectangle from the document stencil onto the page in one motion, all four glue points function normally until the shape is dropped on the page. However, if I take a new rectangle and just drop it somewhere on the page and then try to connect it to an existing rectangle, only the bottom glue point works, i.e., I can glue the bottom of a rectangle to the bottom of another rectangle (the two rectangles overlap), but the glue points on the top and sides don't do anything. This behavior doesn't appear on other pages in the same document with fewer objects on them. Also, if a rectangle isn't working, I can delete all but one of the glue points, and then that glue point will start working again.

I suspect there must be some limitation in Visio related to the number of connection points or objects on my page. Am I right about that? Is there a way to change it?

I've already fixed the registry setting that causes complex objects to not show a bitmap image when you drag them, preventing them from gluing, but that didn't solve this problem. I've also set SnapToShapeComplexity entry in the registry to 1000. Also, I've tried zooming in as far as possible, and the non-functioning glue points still won't work.