This is probably already known, but my initial search found nothing.
 
When I try to ctrl-shift drag a copy of a clip from one take lane to another, it appears to do nothing, but even worse it is placing a copy of the clip on top of the previous clip, making the volume louder.    It also places a dotted line around the border of the clip.  What does this mean.  
 
The work around I'm using for now is to select only a portion of the clip, then ctrl-shift drag works as expected and there is no dotted border.
 
I'm using X3e now.

Works fine here (although I experienced the same issue once, but couldn't reproduce it after reopening the project). The dotted outline means the clips are linked. If you don't want to create a linked clip, simply disable "Copy Entire Clips as Linked Clips" in Edit > Preferences > Customization > Editing.

Actually, now I cannot reproduce the issue.  Maybe all I need to do was close/re-open when this happens.
Thanks for the linked clip info too!