So, I think comping is fantastic in Sonar Platinum but I'm having one issue. For some reason, I'll occasionally lose the ability to comp like normal. In the project I'm working on right now, for example, I can't use the comping tool on a particular tracks. It won't select the clips or turn them "red" like on other tracks. And when I choose a selection it normally "auto-splits" to create a comp region but that stopped working as well. Is there someway to reset the comping for a track so it functions like it should? Sonar seems confused for this particular track.

hummm, I have never had a issue quite like that even though I do have some issues almost every time I use comping. Double check that the smart tool is still selected.  Can you go to another track and does it behave the same?

Is it possible that the clip is locked because the comp was flattened at some point?  Right click on the clip and mouse over Clip Lock to remove any locks that may be in place.

Meant to post this a couple days ago, but apparently it never went: Make sure the Edit filter on the track is set to Clips.

Good points.  You can check the clip inspector for the lock state with the region selected (although a lock icon on the clip is a good clue)
Otherwise, check the edit filter on the track which you can also do by hitting T while the mouse is over the track so that it's not necessary to expand the height to get the control.

Yeah, I run into some comping issues pretty frequently but nothing that kills a project or anything.  I'll often get the "audio engine dropout" error when speed comping, and the ability to flatten a comp is inconsistent - sometimes the comped clip has a blue bar across the top and sometimes it doesn't.  And occasionally when I bounce the clip to a new track, the resulting track will have doubled vocals, but overall, I find comping to be a very useful tool and can live with the occasional hiccups.