I've been racking my brain all evening on this one for the past couple days.  I've tried various export and preference settings...but can't seem to resolve the issue.  Everything sounds right in the original project, but when I export it...whether to WAV (broadcast or not) or MP3...everything is slightly sped up to the point that the pitch is about 1/2 step higher on the exported file.
 
Any thoughts?
 
My basic setup:  Sonar X3 Producer, Presonus StudioLive 16.4.2 mixer, Windows 10 Home

I am not at my DAW so can't check anything but mis-matching sample rates are known to cause this issue on importing audio

If you are playing back at a different sample rate (in a different programme?) there might be an issue if your audio interface is set to a different sample rate than your audio

I can't think through how this might affect exporting but may help steer you in the right direction until someone else can chime in

Interesting....after reading similar posts here, I exited Sonar X3, then changed my Windows settings.  Regardless of bit depth settings, if I set the Windows Playback device sample rate to 48kHz, the exported files play at normal speed.  If I set the sample rate to 44.1kHz, they play fast and at a higher pitch, as explained earlier.  However, when I exported the various MP3 and WAV files to disk, my export settings were for CD...44.1kHz, 16-bit.

Thanks for the quick response, Boydie.  You're on the right path...I'm now trying to narrow it down, as I've found I can make the files play correctly by playing with my Windows Playback Device settings...but by setting them to 48kHz rather than 44.1kHz.  Strange since I supposedly exported the audio at 44.1kHz/16-bit.  
 
I did have my Windows setting at 48kHz.  If memory serves, I had Sonar set to record at 48kHz/24-bit for the entire recording session...15 songs + multiple takes...  It is definitely set that way now.
 

Sounds like a sample rate mismatch. The usual cause of this slight frequency error problem is playback of a 44.1K samples per second recording at 48K. In that case you should also find that the piece is playing about 8% faster than expected, but that timing difference is sometimes less noticeable than the pitch difference. Usually this happens when the audio interface is set at one sample rate and Sonar or another audio program is set at another rate. Not all audio interface drivers will pick up the Sonar sample rate setting, and sometimes other programs will take control of the audio interface driver and reset the interface sample rate after you think it is set to match the project rate. 
 
http://taperssection.com/index.php?topic=80888.0
 

Ok...so everybody was on the right path.  Unfortunately some of the referenced discussions listed old utilities that either had dead links or simply didn't work for me in Windows 10.  This particular discussion, however, did help me resolve my issues: http://forum.cakewalk.com/Recorded-at-wrong-sample-rate-need-to-edit-WAV-headers-to-fix-m2534858.aspx
 
I Downloaded Header Investigator and modified only the sample rate in the headers of of all of my individual track audio files.  They thought they were 48kHz, but I changed them to 44.1kHz, then ensured Sonar and Windows Playback Device was set the same...and everything is happy now.  Strange that I never ran into this situation before.  I've been using Cakewalk and Sonar since at least Cakewalk version 2.1...yes...pre-audio support!  Oh well...resolved!
 
Thanks, all 

Ok...so everybody was on the right path.  Unfortunately some of the referenced discussions listed old utilities that either had dead links or simply didn't work for me in Windows 10.  This particular discussion, however, did help me resolve my issues: http://forum.cakewalk.com/Recorded-at-wrong-sample-rate-need-to-edit-WAV-headers-to-fix-m2534858.aspx
 
I Downloaded Header Investigator and modified only the sample rate in the headers of of all of my individual track audio files.  They thought they were 48kHz, but I changed them to 44.1kHz, then ensured Sonar and Windows Playback Device was set the same...and everything is happy now.  Strange that I never ran into this situation before.  I've been using Cakewalk and Sonar since at least Cakewalk version 2.1...yes...pre-audio support!  Oh well...resolved!
 
Thanks, all