Question : CSS z-index in IE

I think I'm going crazy trying to fix this and am completely stumped.  I have css menu B that works in every browser except for IE.  It's a bit tricky, because I have another css menu A that has to drop over menu B, so if I adjust menu B's settings to be on top, menu A's dropdowns appear underneath menu B.   On top of the fact that the CSS code for this site was generated by Artisteer and I've sort of hacked it a bit to allow me to have two horizontal menus.   As far as I can tell, everything is fine in Chrome, Firefox and Safari, it's only IE 7 and 8 (and I'm sure 6 as well) that have the problem.   Take a look:

http://milwaukeecatholichome.org/m/about-us/

Menu A is art-menu, and z-index is set to 200.  Menu B is main-menu, and I've tried just about z-index number from 1 to 10000 to no avail.  Do I need to post the CSS or can you grab it using dev tools or firebug?

Thanks in advance.

Answer : CSS z-index in IE

Ok add the z-index in as mentioned. Then, increase z-index on art-header to more than the main-nav