File sizes are way too large. I did a test by creating a new document in CS3 and typed the letter "A" on the page and saved. The file comes out to be 1MB.
That should not be that large for one letter typed on a blank page.
I have been working around this issue by opening old documents from previous versions of Illustrator and saving as a different name.
By doing this the same test file using the letter "A" on a blank page comes out at only 100KB.
I have a simple box label with text only in a 4x4 square that was 7MB. That's crazy. I just keep working with old documents to resolve, but it would be nice to see this fixed.