New yarn and 6 cast ons later...

Turns out my problem was DEFINITELY the yarn. It was way too slippery and couldn't hold the stitches in the gauge I was using and since I was at Micheal's with a friend yesterday (she was getting yarn and needles), I spotted some delicious new yarn and scooped it up. It's a worsted weight, not a sport weight, so the gloves will be a bit heavier than the pattern calls for, but the yarn is working fabulously and I haven't had any problems with it!

I did, however, how misunderstand stockinette stitches are done. Specifically, how "st st" is done in the round. At first, I thought st st was knit 1 purl 1, I was close but missing a crucial detail: in flat knitting, it's knit 1 row purl 1 row. The other thing I was missing was when working in the round, st st is accomplished simply by knitting. This only affected two of my rounds, and instead of taking out the two rounds, I left them in, planning on copying the "mistake" on the second glove. I have to say, I rather like the way that it looks leading into my st-st-only rounds. It gives me a very defined cuff, whereas the pattern calls for six rows of garter stitch (which in the round is knit 1 round, purl 1 round btw) and then start the st st which looks fine in the pictures the author included, but looks more like a detailing or embellishment than a cuff.

Cuff with slippery yarn

Cuff with new yarn!

Progress on the body in only a few hours

Now I know the pattern fits :)