Sonar X3. Don't really know what I'm doing right or wrong. Assume long-time newbie please.
 
1.  I exported vocal tracks (44.1/24-bit, triangular, mono), with Sonar's track volume and gain set to zero, and the Master set to zero. (Screenshot of recorded levels): http://screencast.com/t/UTUMUUp0
 
2.  I then imported that track to see the result, which is that the exported track has "gained" dramatically, clipping/distorting the tracks. http://screencast.com/t/EiCwLbgpcEY
 
What should I be looking at to solve this?

First, I see plus signs on your volume and pan widgets, indicating the controls are in Offset Mode. Set the volume back to 0, click the Offset/Envelope button in the Mix module to get back to Envelope mode, and check your Volume setting. If it's adding gain, the exported waveform will come back higher. But it shouldn't be clipping unless the track meter was pegging during playback. Or you exported Master bus or main outs, and there's more gain downstream - possibly on hardware output channel, even. Try exporting with Source = Tracks.

Thank you, it was definitely in Offset Mode and by disabling it everything is back to the way it should be. Didn't do it intentionally, but my dog loves the blue lights so...
 
 

Is the track you are exporting routing to your master bus and going through all those FX again?

Oops didn't read all.

Thanks, gswitz, was just straight exporting by track out the Master Bus, but no effects on. Raw tracks.

Glad to hear that took care if it. Keyboard 'O' is the hotkey for Offset mode in X3 and earlier. This binding was removed in Platinum because so many users were inadvertently enabling it and not realizing. You can re-bind it to some other function or to 'Do Nothing' to avoid this in X3.

Platinum will be installed soon. BUT, a scan of other projects show Offset on in certain ones. I'm grateful it's never skewed me up like it just did, and grateful for your guidance!
 
Peace...

We've all been there.