I have noticed a problem with opening Illustrator ai files in dropbox. If I link all pictures and open later the same file everything works perfectly. If I open an ai file created by someone else, many pictures are not found and I'm supposed to find them and relink. If I relink, the person who created that ai file can not see them anymore and so on. All our team has the same difficulties. And that makes all work very uncomfortable. Maybe you could help us to solve such problem?