Cannot remove clip from timeline

I have just started playing around with Kdenlive.  I have previously used DeVeDe to assemble clips into video DVD's.  I decided since DeVeDe has no actual editing features, I would try Kdenlive.

Here is my problem.  I sucessfully made one video using some VOB files I had ripped off another DVD.  I cut out a portion of one of the Files, only to find it appear at the end of the DVD.  I have no idea why this happened.

Then I started working on a "real project"  which is a collection of clips from old movies downloaded from the internet, mostly on U Tube.

This one is rather lengthy, containing approximately twenty short clips.  When I was dragging the tenth one down to the timeline. It suddenly attached itself to one of the previous clips.  I tried the "remove selected item" command but nothing happened. Likewise I attempted to "snip" sections out using the scissors tool. I successfully removed a large section, however the rest remains.  I was unable to remove it.  I can't figure out why I cannot remove it.  If left there, it will totally ruin my project. Anyone have any clues to what I am doing wrong?