belldiver said..
...Is it the style of kite? the trimming or what?
What.
You must have the zen. Focus Luke! Focus on the force.
Actually it's your lines. If you are sure the wind is steady, clean, non-gusty and consistent, then all kites should behave that way. Tune and re-tune your lines. I do it once a week and sleep with a smile knowing when the weekend comes, it will fly perfectly.