Hello,
I have envelope automation on my master bus in a project in Sonar platinum wich is preventing to stop the project at the end of the song(I think!). I've tried to delete it but it won't go away.
What to do here?

You need to delete the envelope itself by right-clicking on it, not the lane (which just "hides" it).
 
Oh... and make sure the timeline is at a location where that automation parameter is at its desired value before you delete it.  For example, if you had a volume envelope and deleted it, you'd want the timeline to be at a location where the envelope was at zero if that's what the volume should be without the envelope assigned.
 

That's what I did several times but all what happens is that the lane collapses and when I open it again the envelope is still there.
Also there is a greyed out envelope line in the master lane itself

What is automated?
Is the Track View Options menu "Stop At Project End" enabled?

Yes it is, could it have something to do with me copying the project and then shorten it by taking out some choruses?
The volume of the master bus was automated. 

Once volume automation is deleted or the nodes past the end of the project are removed, if the project continues to play past the end, look for more automation nodes or MIDI events in tracks past the expected end of the project. One way to clean up this data is select All, then select From where the project should end and Cut Special. This should remove the data past the end of the project.
 
Once deleted, volume automation will appear if the automation lanes are opened and no other automation lane exists.

Okay Scook, that helped allthough the whole project was deleted at first! When I undid the delete the project was back and stopped at the end,
 
thank you,
 
Toon.
 

tberg@telenet.be
 the whole project was deleted at first

That had to be a great feeling
 
Glad it worked out in the end.

Yes it was! I worked nearly two months on the project!
Luckely for me it was a copy of the project of wich I took out a few choruses so I had the original and could always do the proces over.
Let that be a lesson for everyone before they go over into such editing.