Audio Waveform Bug (redux)

A while ago I posted about how FCP (6.x) has trouble with displaying Audio Waveforms while it's not zoomed in. Today I ran into another interesting Audio Waveform issue again with FCP 6.x (thanks to the client's machine I'm working on).

Here's the before:

You can see that only one waveform is shown and even that's fragmented. The top two audio tracks are disabled via Control + B. When I delete them since they're not needed this is the consistent result:

Suddenly FCP decides to show the lower audio track's waveforms all the time when it was horribly inconsistent before. In fact, it was so bad before that I wasn't able to really edit the audio precisely quickly because the waveforms would come and go. I tried restarting FCP, the Mac, clearing caches (including the waveform cache) and nothing helped until I just deleted the audio tracks that aren't needed anymore (until the client wants them back or some nonsense)