I've coded my megamenu to open using a slide transition.
I'm happy with the appearance, but have noticed a glitch in its operation.
If I scroll down the page after opening the menu, it remains visible and the placement changes to the upper right corner.
Any help is greatly appreciated!
It looks like there is a jQuery plugin altering your menu. It is fixing the megamenu to the top when you scroll down. Here are the details on the specific jQuery plugin, StickUp: http://lirancohen.github.io/stickUp/
Trying removing this script from your page