Comment 1 for bug 172235

I attempted to get around this by attaching connectors to ungrouped "ports" (small circles) and then grouping the ports with their associated objects. This works except that the connectors don't get redrawn when the objects are dragged. (See my Bug #1156977 .)
The connections are actually maintained though because if you save the drawing (with moved objects and "disconnected" connectors) and then reload it the connectors are drawn correctly.