Okey Multiple samples triggered from Edit Mode cannot undo

Hi I have been getting deeper into Renoise LOVING IT so for example I have imported a sample sliced up all good then I go to top right click on added new instrument top right I would go back to the waveform page double click to select that splice the control C copy and then select the new instrument and control V paste in rename and then I have that all good as a new sample I can play up down the keyboard as opposed to be assigned to a single key being externally triggered from my MIDI … not that was great when I was in edit mode each track per sample HOWEVER for some reason I dont understand NOW when I select say Track 3 when I play trigger from external midi it plays two samples at once …and WONT play the splice section which is a new instrument on its own but the previous two or selected two I was probably tired etc.. and clickded did something but its doing my head in for example when I hit record it pops out two notes aa opposed to one .. and not my spliced one which I have assigned as far as I know correctly.. .Please someone help here … I am totally loving this program … its so awesome