I have this problem.
I installed the IG Lightbox of IdealiaGroup and have the problem that the header is above the lightbox. So I changed the theme.css #ja.header z-index to 1 in stead off 9999
Then everything works great, but off course the menu will not go over the slideshow, because the z-index is higher of the slideshow. After changing all the z-indexes to the correct order,
The header keeps popping up in front of the lightbox. The only time the lightbox comes in front of the header is when the z-index of the header is set to 1, what goed wrong here?
Maybe somebody has a solution.
Concerning css’s are menu.css , theme.css and ig_lightbox.css
Solved by installing a different lightbox