Generating an Index from a Book file using FOP

Hello all,

I've been trying to find an answer to this question, but I am not having 
any luck.

I have a book file that contains numerous chapters. I tried placing an 
index element after the last chapter, but the FO file I create seems to 
be invalid.

I'm sure someone must have tried to create an index in a book file. Am I 
missing something? I'm using the latest version of the stylesheets. (1.67.2)

Thanks,

Dave

PS I just tried putting the index inside a <chapter>, and it works fine, 
except that index is in the chapter, and not in a section of its own.