I believe this is a problem related to the slack in the drive mechanism in the equatorial configuration. If the telescope is pointed east, it's "heavier" on that side, so the drive always pushes forward. However, when it's pointed west, it tends to fall into the slack, and it's possible that it "leads" the drive, producing blurry stars.
I've verified indoors that adding 120 grams of weight to the east side of the S30 is enough to ensure that, even past the meridian, the drive always encounters slight resistance, so skipping shouldn't occur. I'll test it as soon as the clouds clear.
