hi, sorry for didn't present very clear.

> Which version of the Ref Manual is this supposed to be?

the newest python documentations, Release 2.6, October 2, 2008

> By Evince do you mean the Gnome document viewer?
> http://www.gnome.org/projects/evince/

Yes

> If so, are you trying to view a .pdf downloaded from python.org?

Yes, from the official site. download the docs from
http://docs.python.org/ftp/python/doc/2.6/python-docs-pdf-a4.tar.bz2

> If so, did you try viewing it with acrobat or some other .pdf viewer?

Yes, the same. I tested in acrobat. both has this problem. 

> This would indicate whether the fault is with the Evince or Python's
> .pdf generation or index support.

I guess the problem is 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.

exactly, the index may be messed up.