Question re: moving clips in Sonar Home Studio creates empty duplicate clips

Hi,
 
I'm a total self-taught (or self-teaching) Sonar newbie, so apologies if this is a dumb question, or if it's been posted elsewhere already, but I'm struggling to find an answer anywhere.
 
I find that when I move a clip using my mouse, tens if not hundreds of empty duplicate clips appear behind it, often running to tens of minutes beyond the length of the song I'm working on. When I go to delete them, they appear to be sitting all over the place, so that sometimes deleting what appears to be an empty track also deletes clips further back in the project that were there to begin with and which I never intended to delete. Often, also, when I attempt to delete these seemingly empty duplicate clips, it sucks all the memory out of the application to the point where it stops responding altogether and I either have to wait for a really long time for it to come back to life, or I have to kill it altogether and just hope that my last save was recently enough not to lose too much.
 
Any help gratefully received, coz this is doing my head in and I don't know why it's happening or how to prevent it.
 
Cheers.

I think this is the answer http://forum.cakewalk.com/FindPost/3602419