Only a minor issue ... but nevertheless I bring it to your attention. I'v just downloaded the 11gr2 documentation and at the top of the starting website I see only some red crosses instead of funny pictures.
The reason is obvious URL (for example) http://download-adc.oracle.com/archive/cd/E23003_01/images/blaf/Oracle_Database_Library.gif
simply does not exist.
And even it WOULD exist, it doesn't make really sense to include references to websites in an offline documentation.