You don't let us know anything about the process and settings you used to create the PDF. Did you choose to embed fonts? Are you doing any color conversion? Are you making the file compliant with any international standard? Also, it appears from the screen shot that you are using a PDF viewer other than Pdf To Word Conversion or Reader. Perhaps trying it in those products will produce a better quality result.
And if you are using Mac OS X, you should be able to find these programs. If you are trying to make a new PDF document in Google Documents and do not want to send your document.