When I nudge ductwork (using the arrow keys), the associated connections (fittings) move and adjust to suit. If I use the move command to move a piece of ductwork a specific distance, the ductwork becomes disasociated from the connections.moveDuct.JPG
This must be a Project specific setting somewhere as I have this same anomily on only some of my models.
The same thing happens with Pipework as well.