Hi Steve,
There are a couple of possibilities that spring to mind that might stop the clicks from working.
1. The Drum track is frozen. If this is the case, simply unfreeze the Drum track, regenerate it and re-freeze it.
2. Another possibility is that the song was rendered when you had a fill as your lead-in. If this is the case, the clicks may be playing but they would be overlaid with the rendered song. To check this, go to the Audio track, left click and see if it's possible to mute the audio.
If muting the audio solves the problem, then it's possible to use the "Kill audio" option to remove the rendered file.
Let me know how you go.
All the best,
Noel