I have a MIDI track that's linked to Konakt. Despite me having never knowingly added any automation lanes for this track, I see that every time I hit play the instrument volume level is snapping to a particular level in Kontakt. Opening the automation lanes I see that there is a lane titled "Volume (default Ch.1)." I cannot seem to get rid of it. If I right click on the envelope and "Delete Envelope," the lane disappears but as soon as I hit play the automation is back. If I right click in the track pane and select "Remove Automation Lane," the lane is deleted but again as soon as I hit play, it comes back. It just seems like there is nothing I can do to fully get rid of this damn automation. 
 
More weirdness: if I turn off Read Automation on the track, the volume snaps to -6.0 in Kontakt when I hit play. If it's on, then the volume snaps to whatever value is in the automation lane. 
 
So deleting the lane does nothing. Turning off read automation doesn't fix it. 
 
And it doesn't matter where in the project I start playback from.
 
Any ideas? This is driving me insane. 

I've had this issue with Kontakt also, I'm not sure we've gotten to the bottom of it. Anyway, have a look at http://forum.cakewalk.com/Erratic-Kontakt-Volume-m2924084.aspx , there's some analysis there.

Hmm all very weird...I've never seen this particular problem with Kontakt before and I use it lots. 
 
There is definitely something weird ongoing with Native Instruments stuff and Sonar. I had a huge problem a while ago with effects hosted in Guitar Rig having all of their controls zeroed out every time I opened the project. It went away for ages then came back again...eventually I gave up on Guitar Rig. 
 
Anyway I was able to solve the problem by copying all the clips to a fresh MIDI track and deleting the old one.

Just came across this issue, or similar... for me, using DimPro and I added a CC7 volume lane in midi.  I put a few points and now the entire track won't play unless there's a volume point added in the lane???? 
If I delete the points, nothing plays.  I added one point in the lane at the first time the midi is used and it plays, but now I must control volume on the whole track now?  Isn't there a way to delete that volume lane to revert to just the velocity lane?  I haven't copied the midi to a new track yet.