Transparency background's screwed since upgrade

I just did an upgrade to both WP 3.0.6 or whatever the newest one is. I simultaneously upgraded to the newest constructor. My previous version of Constructor was, like, .6 or something, so it was a big jump. But all of a sudden, my transparent background overlay isn’t working in IE, and Firefox on Vista. The top-anchored menu is transparent, but not the main body. I’ve gone to an opaque overlay, but I’d really like that transparency back.

I’ll keep looking, but help s/b much appreciated.