Adobe Acrobat help

I have Adobe Acrobat 7.0 Standard.

When I save a doc in AA (mostly DVD covers I have to create in order to make non-standard packaging “shelf-ready”), when it displays you can see that it keeps all the original components–layers, images, text, whatever–separate to some degree, instead of just being one single object made up of simple pixels. Now, used to, when I went to “Reduce File Size,” it would then convert this file into exactly that. A while back, however, I fiddled with the compatible-version setting, because I was distributing copies of these docs to people on even older computers than mine. Suddenly the “Reduce File Size” doesn’t. I mean, where, before I fiddled with the compatibility setting, it would reduce a file by like 90%. Now, it reduces it infinitesimally, if at all. And I’ve tried it in ALL compatibility settings. No go. And I can’t find any preferences or settings that seem to be relevant, and searching Help leaves me just more confused.

Anyone able to tell me why I can’t Reduce anymore? Thanks.