Even though it shows pan separation in the track view, I get no separation through the head phones. Any helpful thoughts out there?

Can you list some details on your system ? Starting with your audio interface.
 
It could be a number of things:
-Possibly routing through your audio interface.
-Possibly a stereo effect leaking part of the signal.
-Possibly the file itself.
 
Without more information im simply just guessing, the same way you are.

Thanks for the reply Chuck.  I have a new Steinberg UR44 interface.  I just replaced an older Steinberg UR44 because it was determined by myself and a recording specialist at Guitar Center that determined that it was defective.  The older one would not output on master.  Now it outputs on master but with no audio separation even though separation is shown in the track view.  Maybe I need to reload my X2 software?  I'm getting the same issue on all song projects.

im going to go out on a limb and say that it is probably a 75% chance your issue is with your Audio interface routing on your UR44 interface.
ive seen a few others complain of mix settings. do you have it set up, for example your master feeds 1+2 out ?
 
 

Unfortunately I'm not really savvy enough to know if my master feeds 1+2 out.  Maybe I can get advise from Steinberg.  Funny thing is it worked for years with my old interface. Trying to get telephone help from Cakewalk Sonar seems to be impossible.