can you give us a more detailed version of the procedure when you try and record automation?
are you using any hardware to record the movements or are you changing the parameters with the mouse?
..to record automation you should only have to:
- activate write-enable on the track where the reverb's inserted
- press play
- start moving around the parameters in the plugin
when you do this you should immediatly see your movements being recorded on the track as automation lanes