Stxx - never had this issue before. As I mentioned earlier in the thread, I will have to take a stab at this in X3 and make sure that I don't have the issue now, but I can imagine that it would be frustrating and useless for automation for it to behave this way. Almost sounds like there was already automation on the track to have the volume at zero that was being READ while the automation was being recorded, causing the volume to jump to the level that was being read when there wasn't anything actively replacing it in write mode.
Also, regarding the "touch sensitive" part, it's true that they aren't touch sensitive, but you have to barely move the slider for it to engage. Touch sensitive would make it engage when simply touched, not moved. This particular aspect was never an issue for me since the move required to get the fader's attention was so small.