Recorded stereo, but playing back mono

What the hell happened? I had two mics positioned above my drums and set them as a stereo pair in my Roland Studio Capture. I assigned them to a stereo track in Sonar X3. I tapped on the mics and could see (and hear) the level on one or the other side, as expected. While recording, it sounded fine.
 
Now I'm home, listening back, and the overheads are playing back mono, as if both sides were panned in the center.
 
I must be doing something wrong. What could it be?

Yes, I could have just recorded each mic to its own mono track and then pan them left and right, but I didn't.  And I'm sure it was recording fine, with a nice stereo image. Something is happening in Sonar (I think) that is causing the stereo track to lose its stereo image.
 
The mics were positioned well (XY), so there wouldn't be any phase issues between them.

Did the track you recorded have left and right channels, or was it a mono file? I am confused on this. It seems you have a stereo file that "sounds mono"?
 
*If* both channels exist and there was not a great variation between the two, it may sound mono (just louder). Ken's suggestion of bouncing the track and splitting into mono tracks would be a simple check... after doing that, you could phase reverse one mono track and see if they null each other out. If they do not, you have both overheads captured; and it is easier to pan them as separate mono tracks.

1. Make sure the audio track is selected (if only one wave file, can just click on the wave form). The track number highlights blue if selected.
2. Tracks menu (at the top of the Track View) - > Bounce to Track(s)...
3. In the pop up that comes up, it should default to "Destination" of New Track at the next available number. And in the right side of that window choose "Split Mono" under the "Channel Format" option.
4. Select "Okay" and it will bounce the original stereo track to two mono tracks.

Quick Edit - You may want to disable most of the "Mix Enables" at the bottom of that pop up, as it will bake in mutes, FX, etc., which you would not want. I would only leave "Fast Bounce" checked.

Step One: determine whether the recorded track is truly stereo. An examination of the waveform is usually all that is necessary, but not always.
 
Should there be no obvious visible differences between the top and bottom waveforms, it can also be determined by summing left and right and looking at the difference. This isn't as hard as it sounds. Any M/S plugin that lets you adjust Mid and Side levels independently will do. I recommend the free Voxengo MSED plugin over Channel Tools for this.
 
Listen to the track while turning the Side knob up and down. If it's a dual-mono track, meaning the left and right sides were somehow combined during recording, then there will be no change in tone or volume as you move the Side knob. A true stereo track, OTOH, will noticeably change.