Full text search on TEXT field

I've a problem. I'm inexperienced about FTS.
I have a TEXT datatype field in my table and I store MS Word documents.

I want to do full text search on this TEXT datatype field.
So I build catalog and run

"Select * from table where Contains (textfield,'Yusuf')" sql in analyzer.

but null value returns. however I know the table has 3 records.

Anyway, I insert a varchar field in the table and edit my fts catalog.
and then insert 3 records in the table.than rebuild catalog and I try
"Select * from table where Contains (varcharfield,'Yusuf')"
this sql returns true records.

I know that I can FTS in TEXT datatype field but I can't. I don't know why.
I need your help.
thanks alot

YusufBesides,
I insert text in text datatype field and returs true values...

The problem occours when insert only MS Word or MS Excel etc files.