Hi - I don't even know how to describe this well enough but here goes: In Sonar Professional I have a relatively small track number project going. First problem I don't know how happened - somehow my guitar and vocal tracks ended up being part of my Session Drummer 3  Track Folder ! so how do I divorce these from one another? This is probably how all the next happened: 
 
Second and really odd issues: In trying to edit different midi clips in Session Drummer (how I discovered this problem in the first place) from one place to another, I started discovering some drum clips still playing underneath but I could not visualize them. In trying to start from scratch with drums, I even deleted the midi track altogether ---BUT drum clips are still playing!! The Session Drummer folder track shows the blank clip-like segments, titled SD 3...but no midi notes at all. Weirder still - Now if I mute the SD folder track - only my vocal track plays back. If I solo the SD folder track, I hear drums and guitar only !!! If I completely delete the Track Folder --I am left with vocal and drums !!! Yikes! Hope someone can cure me.  A new reality has emerged.  Thanks 

Not sure I understand all the issues, but you can start by right-clicking the guitar and vocal clips and choosing Remove From Folder. Then let us know where things stand.

If Session Drummer is playing without clips in a MIDI/Instrument track and the MIDI portion of Session Drummer is populated make sure the transport in Session Drummer is stopped.

Mostly solved.!!..great idea to remove those tracks from the folder...duh I must have forgot about that right click option. OK next still hearing but not seeing any drum midi or audio clips, out of frustration I deleted SD from the synth rack and then an audio track of my original drum clips for one verse and chorus re appear! So odd! Well I am good now. Inserted another incident of SD back into the SD folder and will dive back in to finish this song.