CCK fields a still indexing even if I uncheck the fields

Hello,

I have a content type 'Subscriber' with 2 CCK fields (node reference to the content type category).
The first allow to affect a category to the subscriber and the second allow to choose which categories offers he wishes to receive.

If I uncheck the second field, and I try a search with the word 'bank' for example, I'd like to have only the subscriber which belong to the category 'bank' and not subscribers which have chosen to receive the bank offers.

Despite have re-indexing the site, the second field is still indexing.

What should I do to exclude this field?

Thanks in advance.