comp tool changes in Platinum?

I recently upgraded to Platinum from X3 Pro.  Under X3 I was fairly used to using the comp tool to record many takes and select the best parts of the various take lanes.  (Although I had anomalies from time to time that I never really understood...)
 
Now using Platinum, I record my takes and see the take lanes just like before.  But when I use the comp tool (actually the smart tool with the comp icon at the lower half of the clip) to slice and select clips from tack lanes, I hear two lanes playing simultaneously.  And I can't seem to figure out how to make it stop.
 
Immediately after recording my takes, the most recent take lane is selected, and if I hit play I hear that final take without any problem.  But if I try to select a segment from another take lane I hear both the new selection and the most recent playing at the same time.  (I'm pretty sure...)  If I select the most recent lane again, I hear one guitar. 
 
Another oddity is that the UI doesn't show the selected take lane clip as being selected until I move on to another region in the take lanes.  So I drag the comp tool to select a time region.  I then use the comp tool to click in that time region within another take lane.  The newly selected lane/time region is played (along with another lane).  The selected lane/rime region is not clearly highlighted. Even in the main track, the time region is grayish.  But as soon as I select a segment from further down the time ruler (I,e. the next clip I want to isolate) then the UI clearly highlights the clip I previously selected.  But alas, even though the UI clearly indicates my selected clip, I still hear two guitars.
 
This is so broke it's unusable.
 
What am I missing?  Help!
 

Healing appears to work.  Isolating clips with the comp tool appears to work.  Except the audio data in the parent track is not being updated to reflect my comp clip selection.
 
I have all clips healed so each track lane is a "comp clip".  I select the various track lane with the comp tool.  Each time playback starts over at the start of the track lane.  (good)  The selected track lane is highlighted, and I hear the selected track lane.  I can see the newly selected track's data being added to the parent track's audio display, but it seems to be merging the selected data with the data from the last take lane recorded instead of replacing it.
 
If I manually solo the track lane I want, I still hear the parent tracks audio (the last track recorded).  If I delete the parent tracks audio, then I can hear the track I want solod properly, but that appears to delete all the take lanes audio data too.  (Ir really doesn't cause I can hear the solo'd take lane...
 
If I create a new audio track, create 12 take lanes, copy the audio from the take lanes I have now, and then try comping on the new track, should it work?  Too many hours spent.  I'm about ready to record the part all over, maybe in a new project...
 
Keith
 

1) Sounds like it could simply be a corrupt project.
 
2) In the project you were having problems with scroll through all your take lanes/clips. Based on some of your statements it sounds like possibly you have TWO clips from different lanes unmuted at the same time. Under some circumstances if you record a new set of takes and/or record in a different position and/or edit something oddly a previous take can remain active and audible despite the fact you have used the Comp tool to "promote" another clip (so both clips play and sum like you seem to be describing). That should be apparent by just looking through the Lanes for ANOTHER unmuted clip. It could also be that due to project corruption this is happening as a glitch and not showing itself graphically (if that makes sense).
 
3) There are supposed to be some "improvements" to Take Lanes in the near future (or they may have already been released) so the nature of how Lanes/Comping works indeed might be (or already has) changed. I'm still on an older version of SPlat so I can only speak to the old way for now.
 
 
Cheers.

Are you sure that it isn't just clips being unmuted unwittingly instead of corrupt files? Maybe a mute bug? Just a thought.