If you have streaks while using a tracker, your first assumption should be an alignment error. A close second would be to verify that you don't have a rate error (i.e., you're tracking sidereal while shooting stars, not lunar or solar rates).

If all of the streaks in your image converged towards a single point, that would indicate the lens zoomed in or out gradually during exposure. But your image doesn't show that. Notice that the streaks on the right side tend to converge towards one region, whereas the streaks on the left somewhat converge towards a different region. I've highlighted some of the "vector paths" below.

If a conventional tracker is not correctly polar aligned, or if it has some errors in its precise GPS location and attitude/orientation, then over an exposure such as your 3-minute exposure, you will get streaks.

The magnitude of the streaks depends on how much alignment error, and where in the sky you point the camera. If you are only one or two degrees off the North Celestial Pole (NCP), and you're also aimed north towards Polaris, you probably won't see streaks over a 3 minute exposure. But aimed toward the celestial equator, where stars appear to be moving fastest, you'll notice streaks.

Over at Pentaxforums.com, their review of the O-GPS1 says:

One major factor in astrotracer accuracy was the angle and direction the cameras pointed. We found that the astrotracer performed the best when pointed at Polaris with decreasing accuracy the closer the camera came to being pointed due East or due West. We also found that angling the camera upward reduced accuracy the closer it came to a 45-degree pitch with accuracy at zero and 90 degrees being basically the same. So a 45-degree camera pitch to the East or West will likely deliver the poorest results where as a zero- or 90-degree pitch to either the North, South, or Zenith will likely deliver the best results.

Based on this, and because you're aiming near the celestial equator (Orion straddles the celestial equator), you're definitely asking the Astrotracer to work near its limits. From what I've read, perhaps you could try to improve your calibration procedure (such as be slower and more deliberate when rolling the camera to calibrate the compass sensors and/or GPS)?