Tracks bouncing ?

[Johnny Tequila]

I made a cover version of a song on MuTools saved it, then opened and added a new audio track and saved again
Later I opened and added a percussion track but no seems my drum samples and piano sample (both imported audio) have bounced to a single track?
Have I done something to cause this?

[mutools]

It's diffult to know what you did. Your description is too vague for me to be able to help.