[TYPO3] indexed_search and categories

[lee perry]

heya,

i'm using indexed_search (version 2.10 on TYPO3 4.2RC1) and in the 
documentation of indexed_search i've read something about categories

plugin.tx_indexedsearch.search.defaultFreeIndexUidList =

with a list of id's (?) but i don't know if this is correct - when i use 
this list with id's of specific pages to get them as categories i've got 
the following error-message:

'NO entry in the $TCA-array for the table "index_config". This means 
that the function enableFields() is called with an invalid table name as 
argument.'

who can help me to understand this error and especially to solve it?
so, is there a way to categorize the search result?


thanx for any help,
lee