bandso
I just selected audio on track 3, why didn't it paste on track 3??
Selecting a clip does not change focus to that track if the focus is elsewhere. And the starting track for a paste operation is always the focused track. So if the last track you had focused (i.e. track name is highlighted) was 18, and you select and copy a clip from another track without deliberately moving the focus to that track by clicking its header, the paste will go to track 18.
This independence of track focus and clip selection is very useful, but it seems to throw a lot of users for a loop. I suppose this is because it's not really clearly documented in the Ref. Guide.