We are on V9-SP5. Recently we've had some "Only valid when activated with the same logical date" rules on our external predecessors inexplicably stop working as desired. The result is they stay blue at run time and block the workflow, even though the external predecessor is not scheduled to run on that day. The operator does a "GO immediate" on the next task, and then the external predecessor turns white/italic as if everything is back to normal.
One hunch I have (but it is only a hunch at this point) is that this only occurs when the schedule object has been manually recycled to pick up new schedule changes.
The workaround we are applying is to modify these external predecessor objects to include a CALENDAR rule that matches the calendar rule of the external predecessor, and turn off the "Only valid..." setting since apparently we can't trust it.
Thought I'd share this in case anyone else has had similar experiences?
Pete