Step sequencer only extends notes

[bri859]

When I step sequence exactly as it's described in the Live manual the notes are always extended instead of a new note being written for each step. Yes, I am letting go of the trigger key after I hit the right arrow key. The only way I can get Live to record individual steps (instead of extending them) is to hit the right arrow key one more time after I've programmed a step and then hit the left arrow key to jump back to where I was and then proceed with programming that next step. The same thing happens whether I use my Novation Remote SL or the computer keyboard to trigger the note. Is this a bug or am I missing something simple. Any help would be appreciated.