Mono tracks 3db lower in X3c? (solved)

Hi all,
 
I tried searching for this and found no results so apologizing in advance and hope this is an easy thing to track down.
 
Have been working in X3b (which is awesome) and recently updated to X3c.  What I have found is that the main project I am working on has a volume difference between these 2 versions - using the exact same project file. 
 
I have used restore points and exported audio clips in both to compare and sure enough they are different.
 
My first thought was that maybe my panning law preference had been changed/lost during the update so I checked, but it is showing up as the same (3dB center, sin/cos taper, constant power) in both.
 
The level reduction seems to mainly be in my rhythm guitars that are panned hard right and left. 
 
Has anybody else experienced this?
 
Thanks in advance for any help.
 
Paul

Thanks Brundle, I should have been clearer, it's not just on export that i hear the difference - I did the export just to be able to compare after doing the system restore.
 
Following your logic though, I already had it off in both playback environments...  But I hear the level difference in both playback and export, so it doesn't seem to be the 64 bit engine that is the culprit here.
 
Thanks for the suggestion :)

Thanks Sid.  I did a search like you suggested but only found info about panning laws. I experimented with the information on this page - http://www.cakewalk.com/Documentation/default.aspx?Doc=SONAR%20X2&Lang=EN&Req=Playback.27.html - which does have an INI file setting that does not seem to help my situation. 
 
What I have discovered is that it really has nothing to do with panning laws - I created a simple one track project and it appears that mono tracks are 3db quiter in X3c than they are in X3b, regardless of panning law used. 
 
Now it seems to me there must be more to it than that otherwise more people than just me would be running into this.  But I haven't figured out what that other piece of it is yet.

Ok sorry for the scare - it looks like the actual errant behavior is related to one plugin (Recabinet 3.5.0) and it is X3b that actually is handling the plugin in a way that ends up boosting the track level by 3db.
 
Starting in X3b with my recorded (mono) track and no plugins, I add Recabinet.  So far the levels are correct.  When I save and exit the project and come back in, the track is louder by 3db.  If I remove the plugin and then add it again the track is back to the correct level.  Again if I save/exit and come back in, the track is louder.  This does not happen in X3c.  in X3c the track stays at the correct level thru saves (yay!). 
 
One thing I noticed is that there is a visual indicator in Recabinet for panning within the plug - indicating the plug has been loaded in stereo mode.  In the X3b save/exit reload behavior, this indicator goes away, indicating that the plug has been loaded in mono mode.  So that's different.  In X3c, the panning indicator persists through saves/exits and reloads.  The X3c behavior is much more desirable, obviously.
 
Another benefit I noticed is that in X3b after doing the save/exit/reload, switching the track to stereo doesn't quite work as the plugin only seems to be affecting the left side (likely because the mono version of the plug is being used?) While in X3c I can toggle back and forth correctly between mono and stereo.
 
So in summary, it seems that X3c fixes some oddball behavior with mono plugins, or at least for the Recabinet plugin. 
 
So I'm sticking with X3c and just adjusting my levels going forward.
 
Thank you all for your help.
 
Paul