Use Case Links are broken ?

[colinc]

I have a large number of Use Case Links in my model. These were generated by dragging Use Cases from the project view onto various Activity Diagrams. In this way I maintain linkages between different Use Cases in different business processes.

The problem is that the UseCaseLink this generates now appears to be broken. If I attempt to navigate to any other use cases from the Link tab in a Use Case I get an UnknownConnector:3552 UseCaseLink .  I'm sure this used to work.  Has anyone else experienced this or found any ways around it ?

I am using build 792

Thanks, Colin