I know I've posted about this before, this was more of an issue with colliders not updating correctly when using NGUI in conjunction with iTween. This seems to have resolved itself in one of the updates, not sure.
My main question is actually what peoples' performance experience with NGUI has been when used in conjunction with iTween. I have a fairly simple tabbed menu layout, using a parent panel and sub panels for all the tabbed menus. When tweening the entire layout from the parent panel, it is extremely slow. I'm talking 5 - 10 fps here, and it's very ugly. What exactly needs to be done for tweening a panel that has quite a few objects on it? Is it just not feasible to expect smooth tweening when there are quite a few visual elements in a panel?