Couple of possibilities....
1) The $1938 balance CC was viewed as maxed and therefore paying it down, even by less than you did, removed that maxed ding and thus FICO increased by a greater amount.
2) SW alerts only throw out the latest score. It doesn't tell you specifically why your score changed; only gives ideas. For example, I once got a SW alert for +20 because I added an inquiry. Inquiries don't increase scores but it was a baddie removed that SW doesn't alert for that resulted in the increase. In other words, the +1, or the +19 if from SW alerts, is the result of one or more changes to your report. The +19 makes sense. There could be other things happening to hinder any score change on the +1.
3) +1 is actually reasonable. I once went from 89% to 1% and gained 125 on EQ FICO. Most of the points received came when util hit below 30%. Your util is still high where it's at now and you're still being dinged quite heavily (I'm assuming util is listed as a neg. reason). Five percentage points crossing into 37% likely wouldn't result in much of a gain. Now had it continued into 29%, for example, then I'd predict a nice double-digit increase.
