First off does anyone know how to submitt a bug report for Illustrator CS?

Second, I like to have PDF compatability turned on so I can open the file in other programs such as Acrobat or Preview. I've encountered this problem and have posted it to the AI forum at Adobe's website.

My Problem and Solution:

I had a problem where an 2.2MB AI10 file balloned to 21+MB when saved with PDF compatability turned on. Here is my workaround for the problem:

In AICS's Color Settings dialog box set the settings popup to Emulate AI6 at the very top of the list. When saving the file with PDF compability turned on the file size should now be around 1.5 to 2X of the orginal file. If you set color settings to anything else, such as US Prepress Defaults, it will ballon the file size as much as 15 to 20 times its orginal!

I've tested this on 3 different installs of AICS and all behave the same.

This is not much of a solution for someone who needs the other color settings but it helps if you don't.

Hope this helps.
Toby

It was stupid, but Adobe eliminated their "report a bug" page. In other words, if you run into a bug, too bad. Now they expect you to use snail mail. I guess if it is worth it enough to do it this way, it is worth their attention.

However, posting at the forum site might get you some attention.