Muted Tracks

Since using Sonar Platinum I'm having problems with muting on tracks I don't want muted. I have sound on sound set in preferences. When I punch in some of the tracks don't play back and are grayed out. This happens when I hit record. I have to go to the track and unmute it to hear the playback. I didn't have this in X-3. What am I doing wrong or haven't set up right? Thanks for any input!