This indicates that your pdf reader needs to be reinstalled or updated. It is having problems reading the astrology glyph font. This is known to happen with old or broken versions of the adobe 'acrobat' reader. The latest as of January 2009 is version 9. Acrobat can be tempermental and breaks down a lot, also this document has lots of fonts and graphics in it that tax the limits of the program.
You can download the latest version here,
http://get.adobe.com/reader/?promoid=BUIGO

However we also recommend another pdf reader program called Foxit Reader, this program seems more reliable and simpler and faster, we've never had any problems with it.
http://www.foxitsoftware.com/downloads/