Track Automation in Logic 10 no longer works on multiple tracks - how can I restore track automation so it is responsive again?

Track Automation in Logic 10 no longer works on multiple tracks. I recorded 20 tracks of vocals with the Classic Vocal effect on. After editing I drew track automation control points on all of the vocal tracks. Later I decided I wanted to equalize my vocals on individual tracks. I then reset the channel strip for all the vocal tracks and removed the Classic vocal effect. Unfortunately the reset had the result of raising the vocal volume level too high so I tried to re-adjust the track automation to make the vocals quieter. Now the track automation I did before still shows as the control points look intact, but the actual track automation no longer works. I deleted control points on some tracks and tried re-doing them but it made no difference on the volume of the vocal tracks. Is there any way I can fix this? Is there anything I can do to restore my track automation?