Richard --
Yes, you are correct: when you link two tasks, you show see a thin blue
link line between them in the Gantt Chart view. When you linked the two
tasks, did you select the two tasks, and then click the Link Tasks button on
the Standard toolbar? If you still do not see a link line, you might want
to do the following to see if somebody changed the formatting of your Gantt
Chart:
1. Click Format - Layout
2. In the Layout dialog box, make sure the third Links option is selected,
and then click OK
Let me know if this helps.