There is a serious problem that can and does occur with pro tools automation. It seems to happen more with the volume bar graph. You can make an automation point and it can cause a very noticeable "POP" and or "Click" during playback. You can hear the POP and assume its an analogue noise coming from your vocal chain. After zooming, scrubbing and looking for the offender (which is normally found very easily when zooming and seeing the click on on the waveform) the POP, or Click can be very difficult to find.
Idea No. 1349