Is the waveformm displayed when not in Automation mode?
Have you tried clicking on the waveform zoom tool in the bottom right corner of the Arrange area?
Also, open the Audio Bin from Logic's Window menu. Can you see the waveform for the audio file displayed here?
btw, what version of Logic 9 are you running... and I assume you can't be on 10.4.11?
Waveform is not visible in automation mode whether it's on of off, it does not show when I toggle the waveform toggle button, when I take the zoom tool to the extreme I get a waveform, as I move from the extreme close up view the waveform disappears immediately.
as for the audio bin, it shows the coloured bars
I'm using snow leopard, and logic 9.1.1
Try opening the Audio Bin (not from the Media tab - but from the Window menu) - are any audio files there showing waveforms when you zoom in?
Try selecting the audio regions and choose:
Options > Audio > Refresh Overview(s)
Does this happen in other projects?
Have you tried quitting and restarting your Mac?
Also try importing the audio files into a new project.
Hope one of these remedies the situation.