on the 4d..even keeping still it seems to want to figure 8. i'm assuming its swirly winds...but dunno.
Have you checked your lines to make sure they are the same length? If one side is shorter than the other, the kite interprets that you are pulling on that wing even though that's not what you intend.
Also, how long are your flying lines? As a beginner, when I tried very short lines (40'), I found it much harder to stabilize even a big slow kite (e.g., 8' ProDancer-SUL). I think it is because my hand movements were too jerky and heavy-handed, which caused the kite to over-rotate and, then, I compensated too much the other way and the result might have been compared, loosely, to erratic figure 8's.