Crashes, crashes and more crashes...

Hi, 

In a course, I had to buy a book and use Digital Editions to read it.. However, it is extremely difficult to read and highlight in the book, as the program crashes every single time and does not save my highlights on the different pages - so I have to highlight it all over again. I can see this is a general problem with version 4.5, so I figured I should try downloading version 3.0. However, I am unable to do so. The link provided for download do just not work. Can you please help out with this?