that sounds like a bobble to me. what i would do is watch the video on this
page for Kf&b and repeat it without taking the work off the left needle until the second set of them is done (hope that make sense.) Then you will take the four stitches you have on the right needle and take the second, third, and fourth stitch from the tip and pass it one at a time over the stitch closest to the tip.
hope that helps.
editied to add the link