z-index fun in opera

http://67.100.157.185:8080/about/

hey everyone,

have quite an interesting problem:

on mac safari & firefox, and pc firefox and ie this issue doesn't display--only on opera pc and mac is the problem visible.

here's what i'm trying to do: keep the gray image underneath the content just as it is under the top navigation, logo, and title text.

needless to say i tried using the same code on the three column rules ( as it displays fine in all the aforementioned browsers), but something's not clicking.

any ideas or se something i don't?

thanks!

http://67.100.157.185:8080/about/