Which version of the Ref Manual is this supposed to be?
By Evince do you mean the Gnome document viewer?
http://www.gnome.org/projects/evince/
If so, are you trying to view a .pdf downloaded from python.org?
If so, did you try viewing it with acrobat or some other .pdf viewer?
This would indicate whether the fault is with the Evince or Python's
.pdf generation or index support.

The screenshot shows two other major problems with the TOC.
Data model should not be indented; it is not part of lexical analysis.
Three chapters between Data Model and Compound Statements are missing.